This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A267104 #5 Jan 17 2016 20:25:55 %S A267104 1,3,2,6,4,7,5,10,11,16,22,8,29,12,9,15,37,46,56,67,17,79,92,23,106, %T A267104 30,13,121,38,18,14,21,137,154,172,191,211,47,232,254,277,57,301,326, %U A267104 68,352,80,24,379,407,93,436,107,31,466,122,39,19,497,138,48,25,20,28,529,562,596,631,667,704,155,742,781,821 %N A267104 Inverse permutation to A265903. %H A267104 Antti Karttunen, <a href="/A267104/b267104.txt">Table of n, a(n) for n = 1..10000</a> %H A267104 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A267104 a(n) = (1/2) * ((c+r)^2 - r - 3*c + 2), where c = A162598(n), and r = A265332(n). %o A267104 (Scheme) (define (A267104 n) (let ((col (A162598 n)) (row (A265332 n))) (* (/ 1 2) (- (expt (+ row col) 2) row col col col -2)))) %Y A267104 Inverse: A265903. %Y A267104 Cf. A162598, A265332. %K A267104 nonn %O A267104 1,2 %A A267104 _Antti Karttunen_, Jan 10 2016