A029950 Odd palindromes.

1, 3, 5, 7, 9, 11, 33, 55, 77, 99, 101, 111, 121, 131, 141, 151, 161, 171, 181, 191, 303, 313, 323, 333, 343, 353, 363, 373, 383, 393, 505, 515, 525, 535, 545, 555, 565, 575, 585, 595, 707, 717, 727, 737, 747, 757, 767, 777, 787, 797, 909, 919, 929, 939, 949

Offset: 1

Author

Patrick De Geest

Keywords

• nonn
• base

Comments

There are more odd palindromes (A328332) less than 10^K than even palindromes (A328333) because odd palindromes begin with 1, 3, 5, 7 or 9 while even palindromes begin only with 2, 4, 6 or 8. - Bernard Schott, Oct 24 2019

Links

• Philip Mizzi, Table of n, a(n) for n = 1..7110 (terms up to 20000000).
• P. De Geest, World!Of Numbers
• Index entries for sequences related to palindromes

Crossrefs

Subsequence of A002113.

Cf. A029951 (even palindromes), A328332, A328333.

Programs

Mathematica

palindromicQ[n_,b_:10]:=TrueQ[IntegerDigits[n, b]==Reverse[IntegerDigits[n, b]]];Select[Range[1, 10^4, 2], palindromicQ[#]&&Plus@@Drop[DigitCount[#], {1, 10, 1}]==0&] (* Vincenzo Librandi, Feb 07 2014 *)
Select[Range[1,949,2],PalindromeQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 15 2017 *)

PARI

lista(nn) = {forstep(n=1, nn, 2, if (is_A002113(n), print1(n, ", ")));} \\ Michel Marcus, Feb 06 2014

Extensions

Offset set to 1 and more terms from Michel Marcus, Feb 06 2014