A117752 Number of prime 3-digit palindromes in base n.
2, 2, 3, 5, 6, 6, 13, 13, 15, 21, 20, 26, 25, 30, 36, 30, 37, 44, 50, 42, 59, 60, 61, 71, 75, 68, 89, 93, 109, 100, 111, 113, 118, 120, 133, 134, 142, 155, 162, 154, 166, 168, 187, 194, 220, 195, 207, 212, 235, 210, 243, 263, 247, 257, 293, 286, 296, 320, 304, 328
Offset: 2
Links
- Robert Israel, Table of n, a(n) for n = 2..1000
Crossrefs
Cf. A060873.
Programs
-
Maple
f:= proc(n) nops(select(isprime, [seq(seq(i*(n^2+1)+j*n,j=0..n-1),i=1..n-1)])) end proc: map(f, [$2..100]); # Robert Israel, May 04 2020
-
PARI
a(n)=local(t,i,j);t=0;for(i=1,n-1,for(j=0,n-1,if(isprime(i*(n^2+1)+j*n),t++)));t
Comments