a(n) is the smallest integer m such that m-n is composite and phi(m-n) + sigma(m+n) = phi(m+n) + sigma(m-n).

A244448

a(n) is the smallest integer m such that m-n is composite and phi(m-n) + sigma(m+n) = phi(m+n) + sigma(m-n).

Terms

    a(0) =4a(1) =153a(2) =442a(3) =213a(4) =179a(5) =120a(6) =46a(7) =37a(8) =47a(9) =264a(10) =145416a(11) =1101a(12) =107a(13) =79a(14) =71a(15) =78a(16) =716a(17) =637a(18) =98a(19) =249a(20) =71a(21) =126a(22) =13258a(23) =1243a(24) =119a(25) =163a(26) =119a(27) =131a(28) =140497a(29) =381

External references