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 A048945 #17 Feb 16 2025 08:32:40 %S A048945 1,24,30,40,42,54,56,66,70,78,88,102,104,105,110,114,120,128,130,135, %T A048945 136,138,152,154,165,168,170,174,182,184,186,189,190,195,210,216,222, %U A048945 230,231,232,238,246,248,250,255,256,258,264,266,270,273,280,282,285 %N A048945 Numbers whose product of divisors is a fourth power. %C A048945 Different from sequence of numbers which are the cube root of the product of their proper divisors. Compare A111398. %D A048945 Amarnath Murthy, Generalization of Partition function, Introducing Smarandache Factor partitions, Smarandache Notions Journal, Vol. 11, 1-2-3, Spring 2000. %D A048945 Amarnath Murthy, A note on Smarandache Divisor Sequence, Introducing Smarandache Factor partitions, Smarandache Notions Journal, Vol. 11, 1-2-3, Spring 2000. %D A048945 Amarnath Murthy, Some more ideas on Smarandache Factor Partitions, Smarandache Notions Journal, Vol. 11, 1-2-3, Spring 2000. %H A048945 Charles R Greathouse IV, <a href="/A048945/b048945.txt">Table of n, a(n) for n = 1..10000</a> %H A048945 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/DivisorProduct.html">Divisor Product</a> %p A048945 for n from 2 to 1000 do it1 := sort(convert(divisors(n), list)): it2 := product(it1[j], j=1..nops(it1)-1): if it2 = n^3 then printf(`%d,`,n) fi: od: %t A048945 Select[Range[300], IntegerQ[(Times @@ Divisors[#])^(1/4)] &] (* _Jean-François Alcover_, Nov 05 2012 *) %o A048945 (PARI) is(n)=my(f=factor(n)[,2]); gcd(f)*prod(i=1,#f,f[i]+1)%8==0 \\ _Charles R Greathouse IV_, Sep 18 2015 %Y A048945 Cf. A111398, A111399. %K A048945 nonn %O A048945 1,2 %A A048945 _Eric W. Weisstein_