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 A085629 #36 Apr 16 2025 22:33:46
%S A085629 1,4,8,16,32,64,128,144,216,288,2048,432,8192,1152,864,1296,131072,
%T A085629 1728,524288,2592,3456,18432,8388608,5184,7776,73728,13824,10368,
%U A085629 536870912,15552,2147483648,20736,55296,1179648,31104,41472,137438953472,4718592
%N A085629 Let b(n) equal the product of the exponents in the prime factorization of n. Then a(n) gives the least k such that b(k) = n.
%C A085629 a(n) <= 2^n. - _Robert G. Wilson v_, Jul 14 2014
%C A085629 a(n) = 2^n iff n is a prime or n equals 4 or 6. - _Robert G. Wilson v_, Jul 19 2014
%H A085629 Robert G. Wilson v, <a href="/A085629/b085629.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from T. D. Noe)
%t A085629 f[n_, i_] := f[n, i] = Block[{d, b, p, x}, p = Prime[i]; b = p^n; d = Divisors[n]; For[j = Length[d], j > 1, j--, x = d[[j]]; b = Min[b, p^x*f[n/x, i + 1]]]; b]; f[1, 1] = 1; Array[ f[#, 1] &, 42] (* _Robert G. Wilson v_, Jul 17 2014, after _David Wasserman_'s PARI program below *)
%o A085629 (PARI) f(n, i) = local(d, best, p, x); p = prime(i); best = p^n; d = divisors(n); for (j = 2, length(d) - 1, x = d[j]; best = min(best, p^x*f(n/x, i + 1))); best; a(n) = f(n, 1) \\ _David Wasserman_, Feb 07 2005
%Y A085629 Cf. A005361, A005934.
%Y A085629 Cf. A005179.
%Y A085629 Subsequence of A181800.
%K A085629 nonn
%O A085629 1,2
%A A085629 _Jason Earls_, Jul 10 2003
%E A085629 More terms from _David Wasserman_, Feb 07 2005