A074396 a(n) = 10 - (p mod 10), where p is the n-th prime congruent to 1 (mod 4) for which p+2 is also prime.

5, 3, 1, 9, 9, 3, 1, 3, 1, 9, 9, 9, 1, 3, 9, 1, 9, 3, 9, 1, 9, 1, 3, 1, 9, 9, 3, 9, 3, 1, 3, 9, 1, 9, 3, 1, 9, 1, 3, 1, 1, 9, 1, 3, 1, 1, 9, 3, 9, 9, 3, 1, 9, 1, 3, 3, 1, 9, 3, 9, 9, 3, 3, 1, 9, 1, 9, 3, 9, 3, 9, 3, 9, 1, 1, 3, 1, 1, 1, 1, 9, 9, 1, 1, 3, 1, 3, 3, 1, 1, 1, 3, 3, 3, 9, 1, 9, 9, 9, 3, 9, 1, 3, 3, 1

Offset: 1

Author

Roger L. Bagula, Sep 24 2002

Keywords

• nonn

Examples

			The first 5 such primes are 5, 17, 29, 41, 101. For these, 10 - (p mod 10) is 5, 3, 1, 9, 9.
		

Crossrefs

Cf. A071695.

Programs

Mathematica

10-Mod[ #, 10]&/@Select[Prime/@Range[1500], PrimeQ[ #+2]&&Mod[ #, 4]==1&]

Extensions

Edited by Dean Hickerson, Oct 09 2002