A089779 Let n range through the odd numbers skipping multiples of 5; a(n) = n-th prime ending in n.

11, 23, 107, 179, 2411, 3413, 5417, 4919, 6121, 5923, 9127, 8629, 9931, 10133, 10937, 11939, 14741, 14243, 16747, 16649, 16451, 18553, 19157, 19259, 22961, 22963, 24767, 25169, 28571, 24373, 28277, 31079, 30181, 29483, 31687, 33589, 33091

Offset: 1

Author

Amarnath Murthy, Nov 24 2003

Keywords

• base
• nonn

Examples

			2411 is the 11th prime ending in 11: (11, 211, ..., 2111, 2311, 2411)
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Programs

Maple

f:= proc(n) local d,k,count;
d:= 10^(ilog10(n)+1);
count:= 0;
for k from 0 while count < n do
   if isprime(k*d+n) then count:= count+1 fi
od;
(k-1)*d+n
end proc:
seq(seq(f(10*i+j),j=[1,3,7,9]),i=0..10); # Robert Israel, Dec 10 2017

Mathematica

NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; f[n_] := Block[{p = 2, c = 0, m = Floor[ Log[10, n] + 1]}, While[ If[ Mod[p, 10^m] == n, c++ ]; c < n, p = NextPrim[p]]; p]; Map[f, Select[ Table[n, {n, 1, 91, 2}], Mod[ #, 10] != 5 &]] (* Robert G. Wilson v, Nov 26 2003 *)

Extensions

Extended by Robert G. Wilson v, Nov 26 2003