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 A055610 #10 Oct 21 2022 21:31:08 %S A055610 0,0,0,1,2,5,9,15,24,36,52,71,95,123,156,195,240,292,350,416,489,570, %T A055610 660,759,868,986,1115,1254,1404,1566,1740,1927,2126,2339,2565,2805, %U A055610 3060,3330,3616,3917,4235,4569,4920,5289,5676,6082,6506,6950,7413,7896 %N A055610 A companion sequence to A011896. %H A055610 <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1,0,0,0,1,-3,3,-1). %F A055610 G.f.: x^3 * (1 - x + 2*x^2 - x^3 + x^4 + x^5) / ((1 - x)^3 * (1 - x^7)). %F A055610 a(n) = -A011896(2 - n). %e A055610 x^3 + 2*x^4 + 5*x^5 + 9*x^6 + 15*x^7 + 24*x^8 + 36*x^9 + 52*x^10 + ... %o A055610 (PARI) a(n) = ceil( n * (n-1) * (n-2) / 14) %Y A055610 Cf. A011896. %K A055610 nonn,easy %O A055610 0,5 %A A055610 _Michael Somos_, Jun 02 2000