A106577 Indices n of perfect squares n^2 which are both the sum and the difference of two primes.

2, 3, 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 22, 24, 26, 28, 30, 32, 33, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 117, 118, 120, 122

Offset: 1

Author

Alexandre Wajnberg, May 09 2005

Keywords

• easy
• nonn

Examples

			a(3)=4 because the third square which is the sum and the difference of two primes (16=4^2) is the 4th one in
the succession of the perfect squares (thus: index 4).
		

Crossrefs

Cf. A106544-A106548, A106562-A106564, A106571, A106573-A106575.

Formula

a(n) = SQRT(A106575(n)).

Extensions

Extended by Ray Chandler, May 12 2005