OFFSET
0,2
COMMENTS
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..10000
Tanya Khovanova, There are no coincidences, arXiv preprint 1410.2193 [math.CO], 2014.
FORMULA
G.f.: (1/4)*(3/(1 - x) - Product_{k>=0} (1 - x^(2^k)))^2. - Ilya Gutkovskiy, Apr 03 2019
MATHEMATICA
P[n_, x_] := (bb = IntegerDigits[n, 2]) . x^Range[Length[bb]-1, 0, -1];
TM[n_] := 1 + Mod[P[n, 1], 2];
a[n_] := Sum[TM[k] TM[n-k], {k, 0, n}];
Table[a[n], {n, 0, 63}] (* Jean-François Alcover, Aug 31 2018 *)
PROG
(PARI) a(n)=sum(k=0, n, (1+subst(Pol(binary(k)), x, 1)%2)*(1+subst(Pol(binary(n-k)), x, 1)%2)) \\ Ralf Stephan, Aug 23 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved