A367716 G.f. A(x) satisfies A(x) = 1 / ((1 + x) * (1 - x * (1 + x) * A(x^2))).

1, 0, 2, 1, 4, 6, 13, 23, 44, 82, 154, 292, 547, 1036, 1943, 3672, 6900, 13022, 24498, 46194, 86958, 163892, 308624, 581532, 1095275, 2063534, 3886876, 7322523, 13793363, 25984580, 48948062, 92209073, 173699564, 327214934, 616397498, 1161163428, 2187371054

Offset

0,3

Links

Table of n, a(n) for n=0..36.

Formula

a(n) = (-1)^n + Sum_{k=0..n-1} a(floor(k/2)) * a(n-1-k).

Prog

(PARI) a_vector(n) = my(v=vector(n+1)); for(i=0, n, v[i+1]=(-1)^i+sum(j=0, i-1, v[j\2+1]*v[i-j])); v;

Crossrefs

Cf. A005043, A367717, A367718.

Cf. A351973, A367713.

Sequence in context: A192781 A253918 A269415 * A019142 A330536 A268573

Adjacent sequences: A367713 A367714 A367715 * A367717 A367718 A367719

Keyword

nonn

Author

Seiichi Manyama, Nov 28 2023

Status

approved