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 A163260 #11 Aug 01 2025 00:11:44
%S A163260 0,0,1,1,7,6,30,43,111,184,553,694,2098,3576,8186,13689,35791,54928,
%T A163260 141366,239002,548162,956743,2328296,3754337,9133084,15963906,
%U A163260 36115030,63177196,148953028,251144293,590484909,1038294564,2335617735,4138282064,9539100013,16441453580,37863251785
%N A163260 Row sums of A163259.
%H A163260 Chai Wah Wu, <a href="/A163260/b163260.txt">Table of n, a(n) for n = 1..3323</a> (terms 1..1000 from G. C. Greubel)
%F A163260 a(n) = Sum_{k=1,..,n} ( Sum_{i=1,..,k-1} mod(binomial(n, k + 1), binomial(n, k)) ). - _G. C. Greubel_, Dec 12 2016
%t A163260 T[n_, k_] := Mod[Binomial[n, k + 1], Binomial[n, k]]; Join[{0}, Table[Sum[T[n, k], {k, 1, n - 1}], {n, 1, 20}]] (* _G. C. Greubel_, Dec 12 2016 *)
%Y A163260 Cf. A163259.
%K A163260 nonn
%O A163260 1,5
%A A163260 _Mats Granvik_, Jul 23 2009
%E A163260 Corrected a(20). _Mats Granvik_, Jul 24 2009
%E A163260 Terms a(21) onward added by _G. C. Greubel_, Dec 12 2016