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 A331130 #12 Apr 19 2024 03:16:19 %S A331130 1,2,4,6,8,10,13,19,23,25,29,33,35,39,47,51,55,59,63,71,75,77,83,95, %T A331130 99,105,117,121,126,131,136,146,150,154,170,178,180,184,196,202,207, %U A331130 212,216,232,240,242,251,269,277,285,293,297,303,315,327,339,343,345,355,365 %N A331130 a(n) = Sum_{i=1..n} u_3(i)*u_3(i+1), where u_3(n) = A034836(n). %C A331130 For background references see A330570. %H A331130 Amiram Eldar, <a href="/A331130/b331130.txt">Table of n, a(n) for n = 1..10000</a> %t A331130 s[1] = 1; s[n_] := Module[{e = FactorInteger[n][[;; , 2]]}, If[IntegerQ[Surd[n, 3]], 1/3, 0] + (Times @@ ((e + 1)*(e + 2)/2))/6 + (Times @@ (Floor[e/2] + 1))/2]; With[{t = Array[s, 100]}, Accumulate[Most[t] * Rest[t]]] (* _Amiram Eldar_, Apr 19 2024 *) %Y A331130 Cf. A034836, A331080. %K A331130 nonn %O A331130 1,2 %A A331130 _N. J. A. Sloane_, Jan 10 2020