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 A264798 #18 Jan 17 2016 20:58:34 %S A264798 1,3,9,5,15,7,25,21,9,35,27,11,49,45,33,13,63,55,39,15,81,77,65,45,17, %T A264798 99,91,75,51,19,121,117,105,85,57,21,143,135,119,95,63,23,169,165,153, %U A264798 133,105,69,25,195,187,171,147,115,75,27,225,221,209,189,161,125,81,29,255,247 %N A264798 Irregular triangle read by rows: odd-valued terms of A094728(n+1). %C A264798 A094728(n+1) comes from A120070(n+2). a(n) approximates frequencies of the spectral lines of the hydrogen atom. %C A264798 Row sums: 1, 3, 14, 22, ... = A024598(n+1). %C A264798 First column: A085046(n+1). %C A264798 Row sums of A261046(n) = 1, 3, 8, 12, ... = A014255(n). See the formula. %F A264798 a(n) = A261046(n)*A167268(n+1)/2, where A167268 is Janet's sequence. %e A264798 Irregular triangle begins: %e A264798 1, %e A264798 3, %e A264798 9, 5, %e A264798 15, 7, %e A264798 25, 21, 9, %e A264798 35, 27, 11, %e A264798 49, 45, 33, 13, %e A264798 63, 55, 39, 15, %e A264798 ... %t A264798 Table[n^2 - k^2, {n, 14}, {k, 0, n - 1}] /. n_ /; EvenQ@ n -> Nothing // Flatten (* _Michael De Vlieger_, Nov 25 2015 *) %o A264798 (PARI) for(n=1,20,for(k=0,n-1,s=n^2-k^2;if(s%2,print1(s,", ")))) \\ _Derek Orr_, Dec 24 2015 %Y A264798 Cf. A014255, A024598, A085046, A094728, A120070, A167268, A249947, A261046. %K A264798 nonn,easy,tabf %O A264798 0,2 %A A264798 _Paul Curtz_, Nov 25 2015