Numbers k such that k+1 is a divisor of 3^k + 5^k.

Terms

a(0) =1a(1) =3a(2) =7a(3) =75a(4) =2355a(5) =11475a(6) =31995a(7) =57075a(8) =80311a(9) =196185a(10) =215325a(11) =335115a(12) =991875a(13) =1009545a(14) =1038375a(15) =1169715a(16) =1185675a(17) =1193655a(18) =3507751a(19) =5503095a(20) =8412525a(21) =8618475a(22) =8670915a(23) =9513075a(24) =11384343a(25) =12689415a(26) =13587735a(27) =13708695a(28) =14101815a(29) =14841255