A329505 Expansion of (1 + x)*(1 + 2*x - x^2) / (1 - x).

1, 4, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4

Offset: 0

Author

N. J. A. Sloane, Nov 20 2019

Keywords

• nonn
• easy

Comments

Decimal expansion of 1309/9000. - Elmo R. Oliveira, May 07 2024

Links

• Index entries for linear recurrences with constant coefficients, signature (1).

Crossrefs

Row 2 of array in A329504.

Essentially the same as A000655.

Programs

PARI

Vec((1 + x)*(1 + 2*x - x^2) / (1 - x) + O(x^80)) \\ Colin Barker, Nov 21 2019

Formula

a(n) = 4 for n >= 3.