login
A080785
Least p-smooth number not less n, where p is the smallest prime factor of n.
1
1, 2, 3, 4, 5, 8, 7, 8, 9, 16, 11, 16, 13, 16, 16, 16, 17, 32, 19, 32, 24, 32, 23, 32, 25, 32, 27, 32, 29, 32, 31, 32, 36, 64, 36, 64, 37, 64, 48, 64, 41, 64, 43, 64, 48, 64, 47, 64, 49, 64, 54, 64, 53, 64, 60, 64, 64, 64, 59, 64, 61, 64, 64, 64, 72, 128, 67, 128, 72, 128, 71
OFFSET
1,2
COMMENTS
a(n)<=2^k for n<=2^k.
a(n)=n for n in A000961. - Ivan Neretin, Apr 30 2016
LINKS
Eric Weisstein's World of Mathematics, Smooth Number.
MATHEMATICA
a[n_] := Module[{p, k}, p = FactorInteger[n][[1, 1]]; For[k = n, True, k++, If[FactorInteger[k][[-1, 1]] <= p, Return[k]]]];
Table[a[n], {n, 1, 100}] (* Jean-François Alcover, Oct 15 2021 *)
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Mar 12 2003
STATUS
approved