A207635 Triangle of coefficients of polynomials u(n,x) jointly generated with A207636; see the Formula section.

1, 2, 5, 2, 11, 9, 2, 23, 29, 13, 2, 47, 81, 55, 17, 2, 95, 209, 191, 89, 21, 2, 191, 513, 591, 369, 131, 25, 2, 383, 1217, 1695, 1329, 631, 181, 29, 2, 767, 2817, 4607, 4353, 2591, 993, 239, 33, 2, 1535, 6401, 12031, 13313, 9535, 4577, 1471, 305, 37, 2

Offset

1,2

Links

Table of n, a(n) for n=1..56.

Formula

u(n,x)=u(n-1,x)+v(n-1,x),

v(n,x)=(x+1)*u(n-1,x)+(x+1)*v(n-1,x)+1,

where u(1,x)=1, v(1,x)=1.

Example

First five rows:
1
2
5....2
11...9....2
23...29...13...2

Mathematica

u[1, x_] := 1; v[1, x_] := 1; z = 16;
u[n_, x_] := u[n - 1, x] + v[n - 1, x]
v[n_, x_] := (x + 1)*u[n - 1, x]
   + (x + 1)*v[n - 1, x] + 1
Table[Factor[u[n, x]], {n, 1, z}]
Table[Factor[v[n, x]], {n, 1, z}]
cu = Table[CoefficientList[u[n, x], x], {n, 1, z}];
TableForm[cu]
Flatten[%]  (* A207635 *)
Table[Expand[v[n, x]], {n, 1, z}]
cv = Table[CoefficientList[v[n, x], x], {n, 1, z}];
TableForm[cv]
Flatten[%]  (* A207636 *)

Crossrefs

Cf. A207636.

Sequence in context: A276609 A292591 A240760 * A205715 A181338 A211175

Adjacent sequences: A207632 A207633 A207634 * A207636 A207637 A207638

Keyword

nonn,tabf

Author

Clark Kimberling, Feb 24 2012

Status

approved