A178378 Products of 2 primes that are the difference of 2 primes.

4, 6, 9, 10, 15, 22, 25, 33, 34, 51, 55, 58, 82, 85, 87, 118, 121, 123, 142, 145, 177, 187, 202, 205, 213, 214, 274, 289, 295, 298, 303, 319, 321, 355, 358, 382, 394, 411, 447, 451, 454, 478, 493, 505, 535, 537, 538, 562, 573, 591, 622, 649, 681, 685, 694, 697

Offset: 1

Author

Juri-Stepan Gerasimov, May 26 2010

Keywords

• nonn

Examples

			a(1)=4 because 4=2*2=(5-3)*(5-3) where 2,3,5 and 5-3 are all prime, a(2)=6 because 6=2*3=(5-3)*(5-2) where 2,3,5,5-3 and 5-2 are all prime.
		

Crossrefs

Cf. A000040, A001358.

Formula

a(n)=A124588(m)*A124588(k).

Extensions

Extended beyond 478 by R. J. Mathar, May 28 2010