A093052 Exponent of 2 in 6^n - 2^n.
0, 2, 5, 4, 8, 6, 9, 8, 13, 10, 13, 12, 16, 14, 17, 16, 22, 18, 21, 20, 24, 22, 25, 24, 29, 26, 29, 28, 32, 30, 33, 32, 39, 34, 37, 36, 40, 38, 41, 40, 45, 42, 45, 44, 48, 46, 49, 48, 54, 50, 53, 52, 56, 54, 57, 56, 61, 58, 61, 60, 64, 62, 65, 64, 72, 66, 69, 68, 72
Offset: 0
Keywords
Crossrefs
Programs
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Mathematica
Join[{0},Table[IntegerExponent[6^n-2^n,2],{n,70}]] (* Harvey P. Dale, Mar 08 2012 *) -
PARI
a(n)=if(n<1,0,if(n%2==0,a(n/2)+2*floor((n+2)/4)+1,n+1))
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Python
def A093052(n): return n+(~(m:=3**n-1)& m-1).bit_length() if n else 0 # Chai Wah Wu, Jul 07 2022
Formula
Recurrence: a(2n) = a(n) + [(n+1)/2] + 1, a(2n+1) = 2n+2.