A087428 a(n) = [(p-1)/2 * (q-1)/2] mod p where p = (n+1)th odd prime, q = n-th odd prime.

2, 6, 4, 4, 14, 15, 7, 9, 24, 11, 32, 33, 13, 15, 46, 16, 52, 19, 19, 61, 22, 24, 75, 77, 78, 28, 28, 86, 99, 34, 36, 105, 40, 114, 41, 124, 43, 45, 136, 46, 146, 49, 149, 150, 56, 59, 58, 58, 176, 181, 61, 191, 66, 199, 69, 204, 71, 212, 213, 76, 234, 79, 79, 239, 252, 86

Offset: 1

Author

Gary W. Adamson, Sep 01 2003

Keywords

• nonn

Examples

			a(3) = 4 = (5)(3) mod 11; p = 7, q = 5; (p-1)/2 = 5, (q-1)/2 = 3.
A087427(5) = 15, A087428(3) = 15 mod 11 = 4.
		

Formula

a(n) = A087427(n+2) mod p.

Extensions

Corrected and extended by Ray Chandler, Sep 16 2003