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A093050
Exponent of 2 in (3^n-3)*2^(n-1).
2
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
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.
a(n) = A093051(n) - 1 = A090740(n) + n - 2, for n >= 1. - Amiram Eldar, Sep 14 2024
PROG
(PARI) a(n)=if(n<1, 0, if(n%2==0, a(n/2)+2*floor((n+2)/4)+1, n-1))
CROSSREFS
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
KEYWORD
nonn
AUTHOR
Ralf Stephan, Mar 16 2004
STATUS
approved