A093050 Exponent of 2 in (3^n-3)*2^(n-1).

0, 0, 3, 2, 6, 4, 7, 6, 11, 8, 11, 10, 14, 12, 15, 14, 20, 16, 19, 18, 22, 20, 23, 22, 27, 24, 27, 26, 30, 28, 31, 30, 37, 32, 35, 34, 38, 36, 39, 38, 43, 40, 43, 42, 46, 44, 47, 46, 52, 48, 51, 50, 54, 52, 55, 54, 59, 56, 59, 58, 62, 60, 63, 62, 70, 64, 67, 66, 70

Offset

0,3

Links

Table of n, a(n) for n=0..68.

Formula

Recurrence: a(2n) = a(n) + [(n+1)/2] + 1, a(2n+1) = 2n.

G.f.: sum(k>=0, t^2(3+2t+2t^3-t^4)/[(1+t^2)(1-t^2)^2], t=x^2^k).

Prog

(PARI) a(n)=if(n<1, 0, if(n%2==0, a(n/2)+2*floor((n+2)/4)+1, n-1)

Crossrefs

Cf. A093051, A093052.

a(n) is the exponent of 2 in A016129(n-1), A024281(n), A024287(n), A066406(n)/2, A071952(n+3).

Sequence in context: A258241 A256739 A267104 * A289194 A321508 A245261

Adjacent sequences: A093047 A093048 A093049 * A093051 A093052 A093053

Keyword

nonn

Author

Ralf Stephan, Mar 16 2004

Status

approved