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 A026103 #11 Sep 16 2019 04:31:16 %S A026103 1,3,7,13,25,36,62,78,126,152,244,266,419,423,637,679,932,1007,1307, %T A026103 1419,1697,1918,2229,2514,2899,3300,3672,4223,4663,5298,5682,6495, %U A026103 6988,7619,8324,9289,9861,11033,11697,12812,13727,14956,16008,17298,18473,19701,21186,22502 %N A026103 a(n) = T(n,1) + T(n-1,2) + ...+ T(n-k+1,k), where k = floor((n+1)/2) and T is the array defined in A026098. %C A026103 a(n) is the sum of the terms of the n-th antidiagonal of triangle A026098. - _Sean A. Irvine_, Sep 16 2019 %K A026103 nonn %O A026103 1,2 %A A026103 _Clark Kimberling_ %E A026103 a(11) onward corrected and more terms from _Sean A. Irvine_, Sep 16 2019