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 A071375 #13 May 28 2014 18:49:29
%S A071375 1,0,2,3,0,5,0,7,0,0,0,6,0,13,0,0,0,10,0,19,0,0,0,14,0,0,0,0,0,29,0,
%T A071375 21,0,0,0,22,0,37,0,0,0,26,0,43,0,0,0,33,0,0,0,0,0,34,0,39,0,0,0,38,0,
%U A071375 61,0,0,0,0,0,67,0,0,0,30,0,73,0,0,0,0,0,57,0,0,0,65,0,0,0,0,0,58,0,0,0,0
%N A071375 Smallest m such that sum of squarefree divisors of m equals n; a(n) = 0 if no solution to A048250(x) = n exists.
%F A071375 a(n)=Min{x; A048250[x]=n}, a(n)=0 if no solutions.
%e A071375 n=256: a(256)=217=7.31, all divisors are squarefree and 1+7+31+217=256=n.
%t A071375 ffi[x_] := Flatten[FactorInteger[x]] lf[x_] := Length[FactorInteger[x]] ba[x_] := Table[Part[ffi[x], 2 * w - 1], {w, 1, lf[x]}] cor[x_] := Apply[Times, ba[x]] t = Table[0, {256}]; Do[s = DivisorSigma[1, cor[n]]; If[s < 257 && t[[s]] == 0, t[[s]] = n], {n, 10^6}]; t
%Y A071375 Cf. A048250.
%K A071375 nonn
%O A071375 1,3
%A A071375 _Labos Elemer_, May 22 2002
%E A071375 Definition corrected by _Jaroslav Krizek_, May 28 2014