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 A078250 #7 Sep 17 2024 22:44:54
%S A078250 1,4,6,32,40,72,49,32,27,0,44,72,468,252,75,32,68,72,494,0,252,22,46,
%T A078250 72,25,52,27,252,406,0,496,32,33,272,35,72,444,532,273,0,984,252,86,
%U A078250 352,225,322,94,2352,735,0,255,52,689,2322,55,2352,57,232,649,0
%N A078250 a(1) = 1, a(n) = smallest multiple of n using prime digits if n is composite else smallest multiple of n using composite digits, with a(n) = 0 if there are none.
%C A078250 Besides multiples of 10, 625 and its odd multiples have a(n)=0. Based on comment by _Robert Israel_ in A078239. - _Andrew Howroyd_, Sep 17 2024
%H A078250 Andrew Howroyd, <a href="/A078250/b078250.txt">Table of n, a(n) for n = 1..10000</a>
%o A078250 (PARI) a(n)={if(n%10==0||n%1250==625, 0, if(n==1, 1, my(S=Set([2, 3, 5, 7])); forstep(m=n, oo, n, my(d=digits(m)); if(0 == #if(isprime(n),select(t->t==1||setsearch(S, t), d), select(t->!setsearch(S,t),d)), return(m)))))} \\ _Andrew Howroyd_, Sep 17 2024
%Y A078250 Cf. A074162, A078239, A078240.
%K A078250 base,easy,nonn
%O A078250 1,2
%A A078250 _Amarnath Murthy_, Nov 24 2002
%E A078250 a(13) corrected and a(29) onwards from _Andrew Howroyd_, Sep 17 2024