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 A293216 #8 Oct 04 2017 14:05:26 %S A293216 1,2,2,6,2,36,2,30,12,108,2,2700,2,180,216,210,2,48600,2,40500,360, %T A293216 1620,2,661500,36,2700,1080,94500,2,153090000,2,2310,3240,3780,1080, %U A293216 4465125000,2,40500,5400,69457500,2,34445250000,2,21262500,4082400,56700,2,560290500,60,127575000,7560,49612500,2,1205583750000,9720,254677500,81000,132300,2 %N A293216 a(n) = Product_{d|n, d<n} A260443(d). %H A293216 Antti Karttunen, <a href="/A293216/b293216.txt">Table of n, a(n) for n = 1..1024</a> %F A293216 a(n) = Product_{d|n, d<n} A260443(d). %F A293216 For all n >= 0, a(2^n) = A002110(n). %F A293216 For all n >= 1, A007814(a(n)) = A091954(n) and A048675(a(n)) = A001065(n). %o A293216 (PARI) %o A293216 A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ This function from _Michel Marcus_ %o A293216 A260443(n) = if(n<2, n+1, if(n%2, A260443(n\2)*A260443(n\2+1), A003961(A260443(n\2)))); %o A293216 A293216(n) = { my(m=1); fordiv(n,d,if(d < n,m *= A260443(d))); m; }; %Y A293216 Cf. A048675, A260443, A293217 (restricted growth sequence transform), A293214 (a variant). %Y A293216 Cf. also A001065, A091954. %K A293216 nonn %O A293216 1,2 %A A293216 _Antti Karttunen_, Oct 03 2017