A278228 Least number with the prime signature of prime(n)+1.
2, 4, 6, 8, 12, 6, 12, 12, 24, 30, 32, 6, 30, 12, 48, 24, 60, 6, 12, 72, 6, 48, 60, 60, 12, 30, 24, 72, 30, 30, 128, 60, 30, 60, 60, 24, 6, 12, 120, 30, 180, 30, 192, 6, 60, 72, 12, 96, 60, 30, 60, 240, 12, 180, 30, 120, 120, 48, 6, 30, 12, 60, 60, 120, 6, 30, 12, 12, 60, 60, 30, 360, 48, 30, 60, 384, 210, 6, 30, 30, 420, 6, 432, 30, 120, 60, 180, 6, 210, 48
Offset: 1
Keywords
Links
- Antti Karttunen, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
-
Mathematica
Table[Times @@ MapIndexed[(Prime@ First@ #2)^#1 &, #] &@ If[Length@ # == 1 && #[[1, 1]] == 1, {0}, Reverse@ Sort@ #[[All, -1]]] &@ FactorInteger[ Prime@ n + 1], {n, 120}] (* Michael De Vlieger, Nov 21 2016 *) -
Scheme
(define (A278228 n) (A046523 (+ 1 (A000040 n))))