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A299174 The positive even integers.

%I A299174 #68 Jul 17 2025 18:56:29
%S A299174 2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,
%T A299174 50,52,54,56,58,60,62,64,66,68,70,72,74,76,78,80,82,84,86,88,90,92,94,
%U A299174 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
%N A299174 The positive even integers.
%C A299174 Possible periods of Post's {00, 1101} tag system. - _Charles R Greathouse IV_, Dec 13 2021
%C A299174 Numbers m such that 2^m - m is divisible by 2. - _Bernard Schott_, Dec 15 2021
%H A299174 Joss Langford, <a href="https://www.archinterface.co.uk/2018/02/integer-sequences">Simple Integer Sequences</a>
%H A299174 James B. Shearer, <a href="http://bit-player.org/wp-content/extras/bph-publications/AmSci-1996-01-Hayes-sequences.pdf">Periods of strings</a>, 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.)
%H A299174 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F A299174 a(n) = 2*n, n >= 1.
%F A299174 G.f.: 2*x/(1 - x)^2; corrected by _Ilya Gutkovskiy_, Mar 29 2018
%F A299174 a(n) = 2*a(n-1) - a(n-2). - _Wesley Ivan Hurt_, Jul 17 2025
%p A299174 A299174 := n->2*n;
%t A299174 Range[2, 180, 2]
%o A299174 (R) seq(2, 180, 2)
%o A299174 (PARI) a(n)=2*n \\ _Charles R Greathouse IV_, Dec 13 2021
%Y A299174 Equals A005843 without the leading zero.
%Y A299174 Bisection of A000027. Complement of A004273. - _Omar E. Pol_, Feb 25 2018
%Y A299174 First row of A083140.
%Y A299174 Cf. A005408.
%Y A299174 Cf. A000325, A047257.
%Y A299174 Essentially the same as A163300, A103517, A051755, A005843 and A004277.
%K A299174 nonn,easy
%O A299174 1,1
%A A299174 _Joss Langford_, Feb 04 2018