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 A045971 #14 Sep 19 2023 01:43:37 %S A045971 8,27,125,81,343,3375,1331,243,625,9261,2197,10125,4913,35937,42875, %T A045971 729,6859,16875,12167,27783,166375,59319,24389,30375,2401,132651,3125, %U A045971 107811,29791,1157625,50653,2187,274625,185193,456533,50625,68921,328509,614125 %N A045971 a(1)=8; if n = Product p_i^e_i, n > 1, then a(n) = Product p_{i+1}^{e_i+2}. %D A045971 From a puzzle proposed by _Marc LeBrun_. %F A045971 Sum_{n>=1} 1/a(n) = (4/5) * A065483 - 7/8 = 0.196827322859... . - _Amiram Eldar_, Sep 19 2023 %t A045971 f[p_, e_] := NextPrime[p]^(e + 2); a[1] = 8; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* _Amiram Eldar_, Sep 19 2023 *) %Y A045971 Cf. A045965, A045966, A045967, A045968, A045969, A045970, A045972, A045973, A065483. %K A045971 easy,nonn %O A045971 1,1 %A A045971 _N. J. A. Sloane_ %E A045971 More terms from _David W. Wilson_