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 A115355 #12 Feb 16 2025 08:33:00
%S A115355 3,17,33,41,66,77,89,117,133,145,153,189,161,225,301,257,324,333,341,
%T A115355 297,432,425,369,517,613,441,521,585,513,809,689,792,657,1001,801,881,
%U A115355 1000,1017,873,945,900,1265,1169,1425,1089,1125,1197,1481,1161,1584
%N A115355 a(n) is the smallest number representable in exactly n ways as a sum of 3 powerful(1) numbers.
%C A115355 Here we are considering powerful numbers (first definition) A001694. Note that, by definition, 1 is powerful.
%H A115355 Donovan Johnson, <a href="/A115355/b115355.txt">Table of n, a(n) for n = 1..1000</a>
%H A115355 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PowerfulNumber.html">Powerful Number.</a>
%e A115355 a(2) = 17 since 17 = 4+4+9 = 8+8+1.
%t A115355 pwfQ[n_] := n==1 || Min[Transpose[FactorInteger@n][[2]]] > 1; lim = 5000; pt = Select[Range[lim], pwfQ]; t = Table[0, {i, lim}]; Do[v = pt[[i]]+pt[[j]]+pt[[k]]; If[v <= lim, t[[v]]++ ], {i, Length@pt}, {j, i}, {k, j}]; Table[Position[t, k][[1, 1]], {k, 60}]
%Y A115355 Cf. A001694, A085252, A085253, A085254, A085255, A063274, A115354.
%K A115355 nonn
%O A115355 1,1
%A A115355 _Giovanni Resta_, Jan 21 2006