A206463 G.f. satisfies: A(x*D(-x)) = x where D(x) = g.f. of A014577, the dragon curve sequence.

1, 1, 2, 6, 19, 63, 220, 796, 2951, 11155, 42846, 166738, 655990, 2604868, 10426448, 42023678, 170407186, 694723354, 2845839124, 11707587484, 48350311989, 200377116719, 833062172188, 3473507707930, 14521668486233, 60859782366097, 255639891601242

Offset

1,3

Links

Table of n, a(n) for n=1..27.

Example

G.f.: A(x) = x + x^2 + 2*x^3 + 6*x^4 + 19*x^5 + 63*x^6 + 220*x^7 + 796*x^8 +...
such that A(x*D(-x)) = x and D(x) is the g.f. of the dragon curve:
D(x) = 1 + x + x^3 + x^4 + x^7 + x^8 + x^9 + x^12 + x^15 + x^16 + x^17 + x^19 + ...

Prog

(PARI) {A014577(n) = if( n%2, A014577(n\2), 1 - (n/2%2))}
{a(n)=local(DC=vector(n+1, k, (-1)^(k-1)*A014577(k-1))); polcoeff(serreverse(x*Ser(DC)), n)}
for(n=1, 61, print1(a(n), ", "))

Crossrefs

Cf. A014577.

Sequence in context: A071969 A063030 A372531 * A148467 A148468 A148469

Adjacent sequences: A206460 A206461 A206462 * A206464 A206465 A206466

Keyword

nonn,changed

Author

Paul D. Hanna, Feb 07 2012

Status

approved