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%I #9 Apr 19 2015 00:54:02
%S 1,2,3,5,4,7,8,6,11,10,12,16,22,29,9,15,37,14,17,46,56,21,28,67,36,13,
%T 79,92,106,121,20,45,137,19,23,154,172,55,66,191,27,35,211,232,254,78,
%U 44,277,18,91,301,326,105,120,352,136,26,379,407,436,466,497,54,153,529,25,30,562,596,171,190,631,65,77,667,704,742,210,34,781,43
%N Inverse to A256995 considered as a permutation of natural numbers, with assumed fixed initial term a(1) = 1.
%H Antti Karttunen, <a href="/A256996/b256996.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>
%F a(1) = 1, and for n > 1: a(n) = (1/2) * ((c+r)^2 - r - 3*c + 4), where c = A256989(n), and r = A256990(n).
%o (Scheme) (define (A256996 n) (if (= 1 n) n (let ((col (A256989 n)) (row (A256990 n))) (+ 1 (* (/ 1 2) (- (expt (+ row col) 2) row col col col -2))))))
%Y Inverse: A256995.
%Y Cf. A256989, A256990.
%Y Cf. also A256998, A255556.
%K nonn
%O 1,2
%A _Antti Karttunen_, Apr 14 2015
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