A091284 - OEIS

A091284

Exponent of 2 in -1+prime[n]^s, if s is an exponent of form 16k-8. Except a(1)=0, a(n)=1+A091283(n).

%I #4 Oct 15 2013 22:32:22

%S 0,5,5,6,5,5,7,5,6,5,8,5,6,5,7,5,5,5,5,6,6,7,5,6,8,5,6,5,5,7,10,5,6,5,

%T 5,6,5,5,6,5,5,5,9,9,5,6,5,8,5,5

%N Exponent of 2 in -1+prime[n]^s, if s is an exponent of form 16k-8. Except a(1)=0, a(n)=1+A091283(n).

%C Exponents of 2 in -1+p^s if the exponent s[u]=(2^u)k-(2^(u-1) comes from other sequence generated with s[u-1] exponent by adding 1 to terms of the "previous" sequence. E.g. s=256k-128 needed an addition of 6 to the terms of A091282.

%t Table[{8*k-4, Table[Part[Flatten[FactorInteger [ -1+Prime[n]^(16*k-8)]], 2], {n, 2, 50}]}, {k, 1, 2}]

%Y Cf. A023506, A007814, A091282, A091283, A090739, A090740, A090129.

%K nonn

%O 1,2

%A _Labos Elemer_, Jan 22 2004