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 A036331 #7 Feb 21 2019 23:17:25 %S A036331 128,192,288,320,352,416,432,448,480,528,544,608,624,648,672,720,736, %T A036331 792,800,816,880,912,928,936,968,972,992,1008,1040,1080,1104,1120, %U A036331 1144,1184,1188,1200,1224,1232,1312,1320,1352,1360,1368,1376,1392,1404,1452 %N A036331 Composite numbers n such that juxtaposition of prime factors of n has length 7. %C A036331 The last term of this sequence is a(919196)=9943081. %H A036331 Nathaniel Johnston, <a href="/A036331/b036331.txt">Table of n, a(n) for n = 1..10000</a> %p A036331 isA036331 := proc(n) local d: d:=ifactors(n)[2]: return `if`(not isprime(n) and add(length(d[j][1])*d[j][2], j=1..nops(d))=7, n, NULL): end: seq(isA036331(n),n=2..1452); # _Nathaniel Johnston_, Jun 22 2011 %Y A036331 Cf. A036326-A036334. %K A036331 nonn,base,fini,easy %O A036331 1,1 %A A036331 _Patrick De Geest_, Dec 15 1998