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

1,1

Links

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

Example

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

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 *)

Crossrefs

Sequence in context: A294255 A088777 A041238 * A146084 A179520 A288406

Adjacent sequences: A089776 A089777 A089778 * A089780 A089781 A089782

Keyword

base,nonn

Author

Amarnath Murthy, Nov 24 2003

Extensions

Extended by Robert G. Wilson v, Nov 26 2003

Status

approved