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A225855 Difference between the number of nonnegative evil and odious multiples of n less than 2^n. 1
-1, -1, 3, -1, 5, 9, -7, -1, 27, 25, 11, 162, 13, 49, 521, -1, 697, 2196, 19, 625, 8435, 121, -23, 59049, 3120, 169, 177147, 2401, 29, 982635 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

It appears that for n = 2^i*p, i>0, p prime, a(n) = p^(2^i) or a multiple of it.

For which n is a(n) negative?

For prime n and related conjectures, see A133954.

LINKS

Table of n, a(n) for n=1..30.

PROG

(PARI) a(n)=sum(i=0, floor(2^n/n), subst(Pol(binary(i*n)), x, 1)%2==0)-sum(i=0, floor(2^n/n), subst(Pol(binary(i*n)), x, 1)%2)

CROSSREFS

Cf. A000069, A001969,

Sequence in context: A029723 A187370 A215456 * A201751 A202504 A055199

Adjacent sequences:  A225852 A225853 A225854 * A225856 A225857 A225858

KEYWORD

sign,hard,more

AUTHOR

Ralf Stephan, Aug 31 2013

STATUS

approved

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Last modified February 23 14:35 EST 2020. Contains 332163 sequences. (Running on oeis4.)