

A249125


Composite numbers which are a multiple of the concatenation of their prime factors A084317.


2



4, 8, 9, 16, 25, 27, 32, 49, 50, 64, 81, 100, 121, 125, 128, 169, 200, 243, 250, 256, 289, 343, 361, 400, 500, 512, 529, 625, 729, 800, 841, 961, 1000, 1024, 1250, 1331, 1369, 1600, 1681, 1849, 2000, 2048, 2187, 2197, 2209, 2401, 2500, 2809, 3125, 3200, 3481, 3721, 4000, 4096, 4489, 4913, 5000, 5041, 5329, 6241, 6250, 6400
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Prime numbers are excluded since they trivially satisfy the condition.
Multiplicity of the prime factors is ignored.
Among the first 10000 terms, the 182 which are not prime powers are of the form 2^h * 5^k.  Giovanni Resta, May 29 2017


LINKS

Giovanni Resta, Table of n, a(n) for n = 1..10000


MATHEMATICA

Select[Range[6400], CompositeQ[#] && Mod[#, FromDigits@ Flatten[ IntegerDigits /@ First /@ FactorInteger@#]] == 0 &] (* Giovanni Resta, May 29 2017 *)


PROG

(PARI) for(n=2, 9999, isprime(n)n%A084317(n)print1(n", "))


CROSSREFS

Cf. A084317, A069872, A224930, A240265.
Sequence in context: A046447 A087244 A080062 * A306531 A088949 A134600
Adjacent sequences: A249122 A249123 A249124 * A249126 A249127 A249128


KEYWORD

nonn,base


AUTHOR

M. F. Hasler, Oct 21 2014


STATUS

approved



