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A079700
a(n) is the 2-adic valuation of the n-th even nontotient.
1
1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 3, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 4, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 3, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 2, 3, 1, 4
OFFSET
1,7
LINKS
FORMULA
a(n) = A007814(A005277(n)). - Michel Marcus, Jul 01 2017
EXAMPLE
A005277(10)=86, therefore a(10)=1.
MATHEMATICA
IntegerExponent[Select[Range[2, 500, 2], invphi[#] == {}&], 2] (* Jean-François Alcover, Jul 01 2017, using Maxim Rytin's invphi function *)
PROG
(PARI) lista(nn)=forstep(n=2, nn, 2, if (!istotient(n), print1(valuation(n, 2), ", ")); ); \\ Michel Marcus, Jul 01 2017
CROSSREFS
Sequence in context: A077619 A376141 A030600 * A357722 A374540 A135362
KEYWORD
nonn
AUTHOR
Jon Perry, Jan 31 2003
EXTENSIONS
More terms from Jean-François Alcover, Jul 01 2017
Offset corrected by Charles R Greathouse IV, Jul 02 2017
STATUS
approved