G.f. A(x) satisfies 2*x = Sum_{n=-oo..+oo} (-1)^n * x^(2*n) * (A(x) + x^n)^(2*n) with A(0) = 1.
A380681
G.f. A(x) satisfies 2*x = Sum_{n=-oo..+oo} (-1)^n * x^(2*n) * (A(x) + x^n)^(2*n) with A(0) = 1.
Terms
- a(0) =1a(1) =2a(2) =7a(3) =28a(4) =122a(5) =564a(6) =2707a(7) =13372a(8) =67593a(9) =347916a(10) =1817244a(11) =9607688a(12) =51316353a(13) =276485966a(14) =1500906317a(15) =8201237354a(16) =45072131590a(17) =248974971580
External references
- oeis: A380681