A281482 a(n) = 2^(n + 1) * (2^n + 1) - 1.

3, 11, 39, 143, 543, 2111, 8319, 33023, 131583, 525311, 2099199, 8392703, 33562623, 134234111, 536903679, 2147549183, 8590065663, 34360000511, 137439477759, 549756862463, 2199025352703, 8796097216511, 35184380477439, 140737505132543, 562949986975743

Offset

0,1

Links

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (7,-14,8).

Formula

From Colin Barker, Jan 22 2017: (Start)

a(n) = 7*a(n-1) - 14*a(n-2) + 8*a(n-3) for n>2.

G.f.: (3 - 10*x + 4*x^2) / ((1 - x)*(1 - 2*x)*(1 - 4*x)).

(End)

Prog

(Magma) [2^(n + 1) * (2^n + 1) - 1: n in [0..200]]
(PARI) Vec((3 - 10*x + 4*x^2) / ((1 - x)*(1 - 2*x)*(1 - 4*x)) + O(x^30)) \\ Colin Barker, Jan 22 2017

Crossrefs

Similar sequences: A085601 (2^(n + 1) * (2^n + 1) + 1), A092431 (2^(n - 1) * (2^n + 1) - 1), A092440 (2^(n + 1) * (2^n - 1) + 1), A129868 (2^(n - 1) * (2^n - 1) - 1), A134169 (2^(n - 1) * (2^n - 1) + 1), A267816 (2^(n + 1) * (2^n - 1) - 1), A281481 (2^(n - 1) * (2^n + 1) + 1).

Sequence in context: A134760 A257290 A371758 * A132889 A245390 A149061

Adjacent sequences: A281479 A281480 A281481 * A281483 A281484 A281485

Keyword

nonn,easy

Author

Jaroslav Krizek, Jan 22 2017

Status

approved