A386524 a(n+1) is the smallest product of two or more primes which sum to a(n), starting from a(1) = 5.

5, 6, 8, 15, 26, 69, 134, 393, 1556, 4659, 9314, 27933, 921327, 85680249, 171360494, 2227686253, 17821489976, 124750429783, 17589810592353, 70359242369396, 11046401051970523, 22092802103941042, 1634867355691634222, 238690633930978585462, 45589911080816909786761, 2963344220253099136138295, 2474392423911337778675332705

Offset: 1

Author

Marc Morgenegg, Jul 24 2025

Keywords

• nonn

Comments

a(1) = 5 is a prime and is not taken as a sum of just itself, but thereafter terms are never prime.

Examples

			For n=2, a(2) = 8 and the possible sums of primes are 2+2+2+2 = 8 or 3+5 = 8 and the smallest product of those terms is 3*5=15 (versus 2*2*2*2=16) so that a(3) = 15.
		

Links

• David A. Corneth, PARI program

Crossrefs

Cf. A056240.

Programs

PARI

\\ See Corneth link

Extensions

More terms from David A. Corneth, Jul 28 2025