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%I #119 Jan 04 2022 19:07:03
%S 1,3,2,5,6,4,7,10,12,8,9,14,20,24,16,11,18,28,40,48,32,13,22,36,56,80,
%T 96,64,15,26,44,72,112,160,192,128,17,30,52,88,144,224,320,384,256,19,
%U 34,60,104,176,288,448,640,768,512,21,38,68,120,208,352,576,896,1280,1536,1024,23,42,76,136,240,416,704,1152,1792,2560,3072,2048,25,46,84,152,272,480,832,1408,2304,3584,5120,6144,4096,27,50,92,168,304,544,960,1664,2816
%N Distribute the natural numbers in columns based on the occurrence of "2" in each prime factorization; square array A(row,col) = 2^(row-1) * ((2*col)-1), read by descending antidiagonals.
%C The array in A135764 is identical to the array in A054582 [up to the transposition and different indexing. - _Clark Kimberling_, Dec 03 2010; comment amended by _Antti Karttunen_, Feb 03 2015; please see the illustration in Example section].
%C The array gives a bijection between the natural numbers N and N^2. A more usual bijection is to take the natural numbers A000027 and write them in the usual OEIS square array format. However this bijection has the advantage that it can be formed by iterating the usual bijection between N and 2N. - _Joshua Zucker_, Nov 04 2011
%C The array can be used to determine the configurations of k-th Towers of Hanoi moves, by labeling odd row terms C,B,A,C,B,A,... and even row terms B,C,A,B,C,A,.... Then given k equal to or greater than term "a" in each n-th row, but less than the next row term, record the label A, B, or C for term "a". This denotes the peg position for the disc corresponding to the n-th row. For example, with k = 25, five discs are in motion since the binary for 25 = 11001, five bits. We find that 25 in row 5 is greater than 16 labeled C, but less than 48. Thus, disc 5 is on peg C. In the 4th row, 25 is greater than 24 (a C), but less than 40, so goes onto the C peg. Similarly, disc 3 is on A, 2 is on A, and disc 1 is on A. Thus, discs 2 and 3 are on peg A, while 1, 4, and 5 are on peg C. - _Gary W. Adamson_, Jun 22 2012
%C Shares with arrays A253551 and A254053 the property that A001511(n) = k for all terms n on row k and when going downward in each column, terms grow by doubling. - _Antti Karttunen_, Feb 03 2015
%C Let P be the infinite palindromic word having initial word 0 and midword sequence (1,2,3,4,...) = A000027. Row n of the array A135764 gives the positions of n-1 in S. ("Infinite palindromic word" is defined at A260390.) - _Clark Kimberling_, Aug 13 2015
%C The probability distribution series 1 = 2/3 + 4/15 + 16/255 + 256/65535 + ... + A001146(n-1)/A051179(n) governs the proportions of terms in A001511 from row n of the array. In A001511(1..15) there are ((2/3) * 15)) = ten terms from row one of the array, ((4/15) * 15)) = four terms from row two, and ((16/17) * 15)) = one (rounded), giving one term from row three (a 4). - _Gary W. Adamson_, Dec 16 2021
%C From _Gary W. Adamson_, Dec 30 2021: (Start)
%C Subarrays representing the number of divisors of an integer can be mapped on the table. For 60, write the odd divisors on the top row: 1, 3, 5, 15. Since 60 has 12 divisors, let the left column equal 1, 2, 4, where 4 is the highest power of 2 dividing 60. Multiplying top row terms by left column terms, we get the result:
%C 1 3 5 15
%C 2 6 10 30
%C 4 12 20 60. (End)
%H Antti Karttunen, <a href="/A135764/b135764.txt">Table of n, a(n) for n = 1..10440; the first 144 antidiagonals of array</a>
%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%F From _Antti Karttunen_, Feb 03 2015: (Start)
%F A(row, col) = 2^(row-1) * ((2*col)-1) = A000079(row-1) * A005408(col-1).
%F A(row,col) = A064989(A135765(row,A249746(col))).
%F A(row,col) = A(row+1,col)/2 [discarding the topmost row and halving the rest of terms gives the array back].
%F A(row,col) = A(row,col+1) - A000079(row) [discarding the leftmost column and subtracting 2^{row number} from the rest of terms gives the array back].
%F (End)
%F G.f.: ((2*x+1)*Sum_{i>=0} 2^i*x^(i*(i+1)/2) + 2*(1-2*x)*Sum_{i>=0} i*x^(i*(i+1)/2) + (1-6*x)*Sum_{i>=0} x^(i*(i+1)/2) - 1 - 2*x)*x/(1-2*x)^2. These sums are related to Jacobi theta functions. - _Robert Israel_, Feb 03 2015
%e The table begins
%e 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, ...
%e 2, 6, 10, 14, 18, 22, 26, 30, 34, 38, 42, 46, ...
%e 4, 12, 20, 28, 36, 44, 52, 60, 68, 76, 84, 92, ...
%e 8, 24, 40, 56, 72, 88, 104, 120, 136, 152, 168, 184, ...
%e 16, 48, 80, 112, 144, 176, 208, 240, 272, 304, 336, 368, ...
%e 32, 96, 160, 224, 288, 352, 416, 480, 544, 608, 672, 736, ...
%e etc.
%e For n = 6, we have [A002260(6), A004736(6)] = [3, 1] (i.e., 6 corresponds to location 3,1 (row,col) in above table) and A(3,1) = A000079(3-1) * A005408(1-1) = 2^2 * 1 = 4.
%e For n = 13, we have [A002260(13), A004736(13)] = [3, 3] (13 corresponds to location 3,3 (row,col) in above table) and A(3,3) = A000079(3-1) * A005408(3-1) = 2^2 * 5 = 20.
%e For n = 23, we have [A002260(23), A004736(23)] = [2, 6] (23 corresponds to location 2,6) and A(2,6) = A000079(2-1) * A005408(6-1) = 2^1 * 11 = 22.
%p seq(seq(2^(j-1)*(2*(i-j)+1),j=1..i),i=1..20); # _Robert Israel_, Feb 03 2015
%t f[n_] := Block[{i, j}, {1}~Join~Flatten@ Last@ Reap@ For[j = 1, j <= n, For[i = j, i > 0, Sow[2^(j - i - 1)*(2 i + 1)], i--], j++]]; f@ 10 (* _Michael De Vlieger_, Feb 03 2015 *)
%o (Scheme)
%o (define (A135764 n) (A135764bi (A002260 n) (A004736 n)))
%o (define (A135764bi row col) (* (A000079 (- row 1)) (+ -1 col col)))
%o ;; _Antti Karttunen_, Feb 03 2015
%o (PARI) a(n) = {s = ceil((1 + sqrt(1 + 8*n)) / 2); r = n - binomial(s-1, 2) - 1;k = s - r - 2; 2^r * (2 * k + 1) } \\ _David A. Corneth_, Feb 05 2015
%Y Transpose: A054582.
%Y Inverse permutation: A249725.
%Y Column 1: A000079.
%Y Row 1: A005408.
%Y Cf. A001511 (row index), A003602 (column index, both one-based).
%Y Related arrays: A135765, A253551, A254053, A254055.
%Y Cf. A000027, A002260, A004736, A064989, A135766, A249746.
%Y Cf. also permutations A246675, A246676, A249741, A249811, A249812.
%Y Cf. A260390.
%Y Cf. A001146, A051179.
%K easy,nonn,tabl
%O 1,2
%A _Alford Arnold_, Nov 29 2007
%E More terms from _Sean A. Irvine_, Nov 23 2010
%E Name amended and the illustration of array in the example section transposed by _Antti Karttunen_, Feb 03 2015
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