login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A322261
Square array T(n, k) (n >= 0, k >= 0) read by antidiagonals upwards: the lengths of runs in binary expansion of T(n, k) correspond to the lengths of runs in binary expansion of n followed by the lengths of runs in binary expansion of k.
0
0, 1, 1, 2, 2, 2, 3, 5, 5, 3, 4, 6, 10, 4, 4, 5, 9, 13, 11, 11, 5, 6, 10, 18, 12, 20, 10, 6, 7, 13, 21, 19, 27, 21, 9, 7, 8, 14, 26, 20, 36, 26, 22, 8, 8, 9, 17, 29, 27, 43, 37, 25, 23, 23, 9, 10, 18, 34, 28, 52, 42, 38, 24, 40, 22, 10, 11, 21, 37, 35, 59, 53
OFFSET
0,4
COMMENTS
The array T is associative.
FORMULA
T(n, 0) = T(0, n) = n.
T(n, 1) = A042963(n+1).
T(n, 2) = A047617(n+1).
T(n, 3) = A047457(n+1).
T(1, n) = A010078(n+1).
T(2, n) = A004757(n) for any n > 0.
A005811(T(n, k)) = A005811(n) + A005811(k).
T(2*n, k) = A163621(2*n, k) for any n > 0 and k > 0.
T(2*n, 2*n) = A020330(2*n) for any n > 0.
EXAMPLE
Array T(n, k) begins (in decimal):
n\k| 0 1 2 3 4 5 6 7 8 9 10 11 12
---+--------------------------------------------------------
0| 0 1 2 3 4 5 6 7 8 9 10 11 12
1| 1 2 5 4 11 10 9 8 23 22 21 20 19
2| 2 5 10 11 20 21 22 23 40 41 42 43 44
3| 3 6 13 12 27 26 25 24 55 54 53 52 51
4| 4 9 18 19 36 37 38 39 72 73 74 75 76
5| 5 10 21 20 43 42 41 40 87 86 85 84 83
6| 6 13 26 27 52 53 54 55 104 105 106 107 108
7| 7 14 29 28 59 58 57 56 119 118 117 116 115
8| 8 17 34 35 68 69 70 71 136 137 138 139 140
Array T(n, k) begins (in binary):
n\k | 0 1 10 11 100 101 110 111 1000
----+---------------------------------------------------------------------------
0| 0 1 10 11 100 101 110 111 1000
1| 1 10 101 100 1011 1010 1001 1000 10111
10| 10 101 1010 1011 10100 10101 10110 10111 101000
11| 11 110 1101 1100 11011 11010 11001 11000 110111
100| 100 1001 10010 10011 100100 100101 100110 100111 1001000
101| 101 1010 10101 10100 101011 101010 101001 101000 1010111
110| 110 1101 11010 11011 110100 110101 110110 110111 1101000
111| 111 1110 11101 11100 111011 111010 111001 111000 1110111
1000| 1000 10001 100010 100011 1000100 1000101 1000110 1000111 10001000
PROG
(PARI) torl(n) = my (r=[]); while (n, r = concat(valuation(n+(n%2), 2), r); n \= 2^r[1]; ); r
fromrl(r) = my (v=0); for (i=1, #r, v = (v + (i%2))*2^r[i]-(i%2)); v
T(n, k) = fromrl(concat(torl(n), torl(k)))
KEYWORD
nonn,tabl,base
AUTHOR
Rémy Sigrist, Dec 01 2018
STATUS
approved