A299174 The positive even integers.

2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144

Offset: 1

Author

Joss Langford, Feb 04 2018

Keywords

• nonn
• easy

Comments

Possible periods of Post's {00, 1101} tag system. - Charles R Greathouse IV, Dec 13 2021

Numbers m such that 2^m - m is divisible by 2. - Bernard Schott, Dec 15 2021

Links

• Joss Langford, Simple Integer Sequences
• James B. Shearer, Periods of strings, American Scientist Vol. 84, No. 3 (May-June 1996), p. 207. (See final page of pdf, and see also pp. 3-4 for an introduction.)
• Index entries for linear recurrences with constant coefficients, signature (2,-1).

Crossrefs

Equals A005843 without the leading zero.

Bisection of A000027. Complement of A004273. - Omar E. Pol, Feb 25 2018

First row of A083140.

Cf. A005408.

Cf. A000325, A047257.

Essentially the same as A163300, A103517, A051755, A005843 and A004277.

Programs

Maple

A299174 := n->2*n;

Mathematica

Range[2, 180, 2]

PARI

a(n)=2*n \\ Charles R Greathouse IV, Dec 13 2021

R

seq(2, 180, 2)

Formula

a(n) = 2*n, n >= 1.

G.f.: 2*x/(1 - x)^2; corrected by Ilya Gutkovskiy, Mar 29 2018

a(n) = 2*a(n-1) - a(n-2). - Wesley Ivan Hurt, Jul 17 2025