A385718 Primes p such that there exists prime q < p such that sigma(q+1) = sigma(p+2) = p + q.

367, 457, 691, 341647, 909091, 1803421, 2640571, 3076903, 3413191, 5228611, 6152383, 6541477, 6545197, 6695503, 10161133, 10770313, 15319693, 31128511, 31687069, 39946483, 52764031, 58886803, 104494483, 207855001, 283882153, 307912921, 309201751, 529570609, 574061053

Offset: 1

Author

S. I. Dimitrov, Jul 07 2025

Keywords

• nonn

Comments

The primes q and p form a P(1, 2)-amicable pair. See Dimitrov link.

Examples

			(179, 367) is such a pair because sigma(179+1) = sigma(367+2) = 179 + 367.
		

Links

• S. I. Dimitrov, Generalizations of amicable numbers, arXiv:2408.07387 [math.NT], 2024.

Crossrefs

Cf. A000040, A000203, A063990, A008333, A259180, A385586.

Extensions

More terms from Jinyuan Wang, Jul 07 2025