login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A029972
Palindromic primes in base 4.
11
2, 3, 5, 17, 29, 59, 257, 373, 409, 461, 509, 787, 839, 887, 907, 991, 4289, 4561, 5189, 5669, 5861, 6133, 6217, 6553, 6761, 7309, 7517, 7789, 7853, 12899, 13171, 13591, 14327, 14347, 14411, 14683, 14747, 14891, 15083, 15227, 15439, 15647
OFFSET
1,1
MATHEMATICA
Do[s = RealDigits[n, 4][[1]]; If[PrimeQ[n], If[FromDigits[s] == FromDigits[Reverse[s]], Print[n]]], {n, 1, 1600}]
(* Second program: *)
Select[Prime@ Range@ 1850, PalindromeQ@ IntegerDigits[#, 4] &] (* Michael De Vlieger, May 14 2017, Version 10 *)
PROG
(PARI) isok(n) = my(d=digits(n, 4)); d == Vecrev(d); \\ Michel Marcus, May 14 2017
CROSSREFS
Sequence in context: A216061 A348062 A349678 * A077498 A118958 A259596
KEYWORD
nonn,base
STATUS
approved