A211537 Smallest number k such that the sum of prime factors of k (counted with multiplicity) equals n times a nontrivial integer power.
4, 15, 35, 39, 51, 95, 115, 87, 155, 111, 123, 215, 235, 159, 371, 183, 302, 335, 219, 471, 395, 415, 267, 623, 291, 303, 482, 327, 339, 791, 554, 1255, 635, 655, 411, 695, 662, 447, 698, 471, 734, 815, 835, 519, 1211, 543, 842, 1895, 579, 591, 914, 2167, 1263
Offset: 1
Keywords
Examples
a(55) = 1964 = 2^2*491, since the sum of the prime divisors counted with multiplicity is 491+4 = 495 = 55*3^2.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000
Programs
-
Maple
sopfr:= proc(n) option remember; add(i[1]*i[2], i=ifactors(n)[2]) end: a:= proc(n) local k, q; for k while irem(sopfr(k), n, 'q')>0 or igcd (map(i->i[2], ifactors(q)[2])[])<2 do od; k end: seq (a(n), n=1..100);
Comments