A167459 Composite numbers in A166504, i.e., whose decimal expansion can be split up into prime numbers, with leading zeros allowed.

22, 25, 27, 32, 33, 35, 52, 55, 57, 72, 75, 77, 112, 115, 117, 132, 133, 135, 172, 175, 177, 192, 195, 202, 203, 205, 207, 213, 217, 219, 222, 225, 231, 232, 235, 237, 243, 247, 252, 253, 255, 259, 261, 267, 272, 273, 275, 279, 289, 292, 295, 297, 302, 303

Offset: 1

Author

M. F. Hasler, Nov 19 2009

Keywords

• base
• nonn

Comments

In contrast to A066737 (which is a subsequence of this one), we allow for leading zeros in the "prime" substrings; the two sequences differ from n=24 on, with a(24)=202 which is not in A066737.

Sequence A166505 gives the difference, A167459 \ A066737 = A166504 \ A152242. Sequence A167458 gives the indices of the terms not in A066737.

Crossrefs

Cf. A002808, A066737, A121609, A166504, A167505.

Programs

PARI

is_A167459(n) = !isprime(n) & is_A166504(n)

Formula

A167459 = A002808 n A166504, where "n" means intersection.

A167459 \ A066737 = A166504 \ A152242.