A035140 Digits of juxtaposition of prime factors of composite n appear also in n.

25, 32, 121, 125, 128, 132, 135, 143, 175, 187, 243, 250, 256, 295, 312, 324, 341, 351, 375, 432, 451, 512, 625, 671, 679, 735, 781, 875, 928, 932, 1023, 1024, 1053, 1057, 1207, 1243, 1250, 1255, 1324, 1325, 1328, 1331, 1352, 1359, 1372, 1375, 1377, 1379

Offset

1,1

Links

Michael S. Branicky, Table of n, a(n) for n = 1..10000

Example

295 = 5 * 59 since {5,9} is a subset of {2,5,9}.

Mathematica

id[n_]:=Complement[Range[0, 9], IntegerDigits[n]]; fac[n_]:=Flatten[IntegerDigits[Take[FactorInteger[n], All, 1]]]; t={}; Do[If[!PrimeQ[n] && Intersection[id[n], fac[n]] == {}, AppendTo[t, n]], {n, 2, 1380}]; t (* Jayanta Basu, May 01 2013 *)
Select[Range@10000, CompositeQ@# && SubsetQ[IntegerDigits@#, Flatten@IntegerDigits@(#[[1]] & /@ FactorInteger@#)] &] (* Hans Rudolf Widmer, May 11 2023 *)

Prog

(Python)
from sympy import factorint, isprime
def ok(n): return n > 1 and not isprime(n) and set("".join(str(p) for p in factorint(n))) <= set(str(n))
print([k for k in range(1380) if ok(k)]) # Michael S. Branicky, May 11 2023

Crossrefs

Cf. A035139, A035141.

Sequence in context: A258876 A263029 A225418 * A050694 A107608 A219951

Adjacent sequences: A035137 A035138 A035139 * A035141 A035142 A035143

Keyword

nonn,base

Author

Patrick De Geest, Nov 15 1998

Extensions

Name clarified by Hans Rudolf Widmer, May 11 2023

Status

approved