A226732 Palindromes that cannot be expressed as a nontrivial product of two palindromes.

1, 2, 3, 5, 7, 11, 101, 111, 131, 141, 151, 161, 171, 181, 191, 212, 232, 252, 272, 292, 313, 323, 343, 353, 373, 383, 414, 434, 454, 474, 494, 515, 525, 535, 545, 565, 575, 585, 595, 656, 676, 717, 727, 737, 747, 757, 767, 787, 797, 818, 838, 858, 878, 898

Offset

1,2

Comments

Complement of A078337.

Links

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

Mathematica

palQ[n_] := Reverse[x = IntegerDigits[n]] == x; t1 = Rest[Select[Range[900], palQ[#] &]]; Join[{1}, Complement[t1, Union[Flatten[Table[i*j, {i, t1}, {j, t1}]]]]]

Crossrefs

Cf. A078337.

Sequence in context: A323697 A103850 A288369 * A083393 A182051 A052480

Adjacent sequences: A226729 A226730 A226731 * A226733 A226734 A226735

Keyword

nonn,base

Author

Jayanta Basu, Jun 16 2013

Status

approved