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 A075356 #4 Dec 05 2013 19:55:37 %S A075356 1,2,7,11,24,33,58,74,115,140,201,237,273,364,413,532,596,747,828, %T A075356 1015,1115,1342,1463,1734,1878,2022,2353,2522,2905,3101,3540,3765, %U A075356 4264,4520,5083,5372,6003,6327,7030,7391,7752,8550,8950,9828,10269,11231,11715 %N A075356 Sum of terms in n-th group in A075352. %F A075356 a(n) = A075355(n)*(A075354(n)+A075353(n))/2. - _David Wasserman_, Jan 16 2005 %Y A075356 Cf. A075352, A075353, A075354, A075355. %K A075356 nonn %O A075356 1,2 %A A075356 _Amarnath Murthy_, Sep 19 2002 %E A075356 More terms from _David Wasserman_, Jan 16 2005