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 A328984 If n is even, a(n)=floor((5t+1)/2) where t=n/2; if n==1 (mod 4) then a(n)=10t+1 where t=(n-1)/4; and if n==3 (mod 4) then a(n)=10t+7 where t=(n-3)/4. 4
 1, 3, 7, 5, 11, 8, 17, 10, 21, 13, 27, 15, 31, 18, 37, 20, 41, 23, 47, 25, 51, 28, 57, 30, 61, 33, 67, 35, 71, 38, 77, 40, 81, 43, 87, 45, 91, 48, 97, 50, 101, 53, 107, 55, 111, 58, 117, 60, 121, 63, 127, 65, 131, 68, 137, 70, 141, 73, 147, 75, 151, 78 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS This is a simplified version of A328190. It does not quite have the defining property of that sequence, which is that the sequence and its first differences together are disjoint. For the present sequence the first differences are in A328985, and the intersection of the sequence and its first differences are the numbers >= 11 that are congruent to 1 (mod 10). The graphs of A328190 and this sequence are essentially identical. LINKS N. J. A. Sloane, Table of n, a(n) for n = 1..10000 FORMULA From Colin Barker, Nov 07 2019: (Start) G.f.: x*(1 + 3*x + 6*x^2 + 2*x^3 + 3*x^4) / ((1 - x^2)*(1 - x^4)). a(n) = a(n-2) + a(n-4) - a(n-6) for n>6. (End) CROSSREFS Cf. A328190, A328196, A328985. Sequence in context: A061026 A064632 A216487 * A328190 A090978 A113830 Adjacent sequences:  A328981 A328982 A328983 * A328985 A328986 A328987 KEYWORD nonn AUTHOR N. J. A. Sloane, Nov 06 2019 STATUS approved

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Last modified May 28 09:52 EDT 2020. Contains 334679 sequences. (Running on oeis4.)