A116037 - OEIS

A116037

Numbers k such that k+prime(k)+prime(prime(k)) is a palindrome, where prime(k) denotes the k-th prime.

1, 17, 20, 29, 253, 344, 370, 445, 479, 675, 786, 887, 1539, 3115, 4221, 4271, 6002, 6416, 7657, 9015, 10003, 11563, 12651, 12984, 14200, 14494, 14880, 14928, 15504, 15738, 17064, 18008, 18265, 18395, 19065, 21795, 23093, 23676, 24078, 24570

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Robert Israel, Table of n, a(n) for n = 1..385

EXAMPLE

10003+prime(10003)+prime(prime(10003)) = 1481841.

MAPLE

ispali:= proc(n) local L; L:= convert(n, base, 10); andmap(i -> L[i]=L[-i], [$1..nops(L)/2]) end proc:

filter:= proc(n) local p; p:= ithprime(n); ispali(n+p+ithprime(p)) end proc:

select(filter, [$1..30000]); # Robert Israel, May 01 2026

CROSSREFS

Cf. A115884.

Sequence in context: A361169 A034069 A340046 * A081643 A146169 A218864

Adjacent sequences: A116034 A116035 A116036 * A116038 A116039 A116040

KEYWORD

nonn,base

AUTHOR

Giovanni Resta, Feb 13 2006

STATUS

approved