a(n) is the least nonnegative integer k such that the 2-valuation of 3^k+5 is n, or -1 if no such number exists.

A368350

a(n) is the least nonnegative integer k such that the 2-valuation of 3^k+5 is n, or -1 if no such number exists.

Terms

    a(0) =0a(1) =-1a(2) =1a(3) =7a(4) =3a(5) =27a(6) =43a(7) =75a(8) =139a(9) =11a(10) =779a(11) =267a(12) =1291a(13) =3339a(14) =7435a(15) =32011a(16) =48395a(17) =81163a(18) =146699a(19) =277771a(20) =15627a(21) =1588491a(22) =2637067a(23) =539915a(24) =4734219a(25) =13122827a(26) =63454475a(27) =29900043a(28) =231226635a(29) =97008907

External references