Least k such that k-2^r is prime for n values of r. Index of the first occurrence of n in A109925.

A109926

Least k such that k-2^r is prime for n values of r. Index of the first occurrence of n in A109925.

Terms

    a(0) =1a(1) =3a(2) =4a(3) =15a(4) =21a(5) =45a(6) =75a(7) =465a(8) =1095a(9) =2145a(10) =4935a(11) =14955a(12) =80685a(13) =229845a(14) =1295325a(15) =1575285a(16) =9700575a(17) =20435415a(18) =15054105a(19) =53999715a(20) =2282745465

External references