A372510 Number of ordered factorizations of 2*n-1 into twin primes.

1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 0, 1, 1, 1, 1, 2, 2, 0, 2, 1, 1, 3, 0, 1, 2, 0, 2, 2, 1, 1, 3, 2, 0, 0, 1, 1, 3, 2, 0, 1, 0, 2, 2, 0, 2, 2, 2, 0, 3, 1, 1, 6, 1, 1, 0, 0, 0, 3, 2, 1, 2, 1, 0, 2, 0, 2, 4, 1, 1, 0, 2, 2, 3, 1, 1, 3, 2, 0, 0, 0, 0, 6, 0, 1, 3, 0, 3, 2, 1

Offset: 1

Author

Ilya Gutkovskiy, May 04 2024

Keywords

• nonn

Examples

			a(23) = 3 because we have 23 * 2 - 1 = 45 = 3 * 3 * 5 = 3 * 5 * 3 = 5 * 3 * 3.
		

Crossrefs

Cf. A001097, A008480, A050328, A050363, A062505, A077608, A164292.

Formula

If 2*n-1 = Product A001097(k)^e(k) then a(n) = A008480(2*n-1), otherwise 0.