A333016 Smallest palindromic number >= 2^n.

1, 2, 4, 8, 22, 33, 66, 131, 262, 515, 1111, 2112, 4114, 8228, 16461, 32823, 65556, 131131, 262262, 524425, 1049401, 2097902, 4194914, 8388838, 16777761, 33555533, 67111176, 134222431, 268444862, 536878635, 1073773701, 2147557412, 4294994924, 8589999858, 17179897171

Offset: 0

Author

Eder Vanzei, Mar 05 2020

Keywords

• nonn
• base

Examples

			a(10) = 1111, because 2^10 = 1024 and 1111 is the smallest palindromic number >= 1024.
		

Links

• Chai Wah Wu, Table of n, a(n) for n = 0..3321

Crossrefs

Cf. A000079, A002113, A262038, A333770.

Programs

Mathematica

spn[n_]:=Module[{k=2^n},While[!PalindromeQ[k],k++];k]; Array[spn,40,0] (* Harvey P. Dale, Jun 12 2023 *)

PARI

a(n) = for(k=2^n, oo, if(Vecrev(v=digits(k))==v, return(k))); \\ Jinyuan Wang, Mar 05 2020

Formula

a(n) = A262038(A000079(n)). - Michel Marcus, May 04 2020

Extensions

a(9) corrected by and more terms from Jinyuan Wang, Mar 05 2020