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Inverse permutation to A170949.
5

%I #18 Jun 20 2018 01:36:49

%S 1,3,2,4,7,6,8,5,9,13,12,14,11,15,10,16,21,20,22,19,23,18,24,17,25,31,

%T 30,32,29,33,28,34,27,35,26,36,43,42,44,41,45,40,46,39,47,38,48,37,49,

%U 57,56,58,55,59,54,60,53,61,52,62,51,63,50,64,73,72,74,71,75,70,76,69,77,68,78

%N Inverse permutation to A170949.

%C a(A002522(n-1)) = A002061(n); a(A002061(n)) = A174114(n). - _Reinhard Zumkeller_, Mar 08 2010

%C Row sums are n^3+(n+1)^3 [A005898](1,9,35,91,189,...). - _Vincenzo Librandi_, Feb 22 2010

%C The even central polygonal numbers divided by 2 give the central column of the triangle. - _Omar E. Pol_, Aug 16 2011

%D J. H. Conway, Personal communication, Feb 19 2010

%H R. Zumkeller, <a href="/A170950/b170950.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> [From _Reinhard Zumkeller_, Mar 08 2010]

%e 1

%e 3 2 4

%e 7 6 8 5 9

%e 13 12 14 11 15 10 16

%e 21 20 22 19 23 18 24 17 25

%e 31 30 32 29 33 28 34 27 35 26 36

%e 43 42 44 41 45 40 46 39 47 38 48 37 49

%e 57 56 58 55 59 54 60 53 61 52 62 51 63 50 64

%e 73 72 74 71 75 70 76 69 77 68 78 67 79 66 80 65 81

%K nonn,tabf

%O 1,2

%A _N. J. A. Sloane_, Feb 21 2010