A308031 G.f. A(x) satisfies: A(x) = x + x^2 + x^3 + x^4 * (1 + A(A(x))).

1, 1, 1, 1, 1, 2, 4, 8, 16, 34, 78, 195, 523, 1472, 4284, 12832, 39608, 126406, 418276, 1436230, 5110170, 18785417, 71109917, 276404921, 1101234823, 4493335194, 18773200580, 80320474041, 351906635253, 1578344960050, 7241981076424, 33961826526634, 162615016927284

Offset

1,6

Comments

Shifts left 4 places under COMPOSE transform.

Links

Table of n, a(n) for n=1..33.

Mathematica

terms = 33; A[_] = 0; Do[A[x_] = x + x^2 + x^3 + x^4 (1 + A[A[x]]) + O[x]^(terms + 1) // Normal, terms + 1]; Rest[CoefficientList[A[x], x]]

Crossrefs

Cf. A030266, A030277, A308030, A308032.

Sequence in context: A248890 A308245 A209971 * A166354 A336009 A180207

Adjacent sequences: A308028 A308029 A308030 * A308032 A308033 A308034

Keyword

nonn

Author

Ilya Gutkovskiy, May 10 2019

Status

approved