A265641 Palindromes in base 10 (A002113) which are also prime factorization palindromes (A265640).

1, 2, 3, 4, 5, 7, 8, 9, 11, 44, 99, 101, 121, 131, 151, 171, 181, 191, 212, 242, 252, 272, 292, 313, 333, 343, 353, 363, 373, 383, 404, 464, 484, 575, 656, 676, 727, 747, 757, 787, 797, 828, 848, 909, 919, 929, 1331, 5445, 6336, 8228

Offset

1,2

Comments

Composite numbers in the sequence have two forms of symmetry.

Links

David A. Corneth, Table of n, a(n) for n = 1..10000

David A. Corneth, n, a(n), symmetric factorization of a(n)

David A. Corneth, PARI program

Example

5445 = 3*11*5*11*3, so it is a term.

Prog

(PARI) isok(n) = (Vecrev(m=digits(n))==m) && (isprime(core(n)) || issquare(n)); \\ Michel Marcus, Jan 15 2019
(PARI) \\ See Corneth link \\ David A. Corneth, Jan 22 2019

Crossrefs

Intersection of A002113 and A265640.

Sequence in context: A230762 A098776 A098897 * A192140 A084092 A288927

Adjacent sequences: A265638 A265639 A265640 * A265642 A265643 A265644

Keyword

nonn,base

Author

Vladimir Shevelev, Dec 11 2015

Extensions

Missing term 8 inserted by Martin Schlegel, Jan 15 2019

Status

approved