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 A274530 #26 Nov 30 2016 01:03:42 %S A274530 1,5,9,16,18,31,43,51,66,77,111,146,128,177,168,202,202,266,296,278, %T A274530 327,388,393,405,553,497,634,690,639,736,809,792,816,816,985,1006, %U A274530 1012,1232,1245,1215,1342,1435,1481,1305,1629,1595,1639,1693,1825,1833,2061,2008,2006,2407,2496,2314,2525,2400,2694,2723 %N A274530 Sum of the n-th antidiagonal of infinite Sudoku-type array A269526. %H A274530 Alois P. Heinz, <a href="/A274530/b274530.txt">Table of n, a(n) for n = 1..2000</a> %F A274530 a(n) = A274652(n-1) + n. %e A274530 For n = 6 the sum of all elements of the 6th antidiagonal of the square array A269526 is 6 + 7 + 3 + 2 + 8 + 5 = 31, so a(6) = 31. %Y A274530 Cf. A269526, A274529, A274652. %K A274530 nonn %O A274530 1,2 %A A274530 _Omar E. Pol_, Jun 29 2016 %E A274530 More terms from _Alois P. Heinz_, Jun 29 2016