A166926 A000004 preceded by 1, 2, 4.

1, 2, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset: 0

Author

Klaus Brockhaus, Oct 23 2009

Keywords

• easy
• nonn

Comments

Inverse binomial transform of A058331.

Crossrefs

Cf. A000004 (zero sequence), A058331 (2*n^2+1), A130706 (1, 2, 0, 0, 0, 0, ...), A130779 (1, 1, 2, 0, 0, 0, 0, ...).

Programs

PARI

{concat([1,2,4],vector(102))}

Formula

a(0) = 1, a(1) = 2, a(2) = 4, a(n) = 0 for n > 2.

G.f.: (1+2*x+4*x^2).

a(n) = 2^n mod 8. - Ridouane Oudra, Apr 08 2025