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The nonnegative integers reordered in groups of 5 even numbers followed by 5 odd numbers.
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%I #14 Mar 18 2023 08:47:08

%S 0,2,4,6,8,1,3,5,7,9,10,12,14,16,18,11,13,15,17,19,20,22,24,26,28,21,

%T 23,25,27,29,30,32,34,36,38,31,33,35,37,39,40,42,44,46,48,41,43,45,47,

%U 49,50,52,54,56,58,51,53,55,57,59,60,62,64,66,68,61,63,65,67,69,70,72,74

%N The nonnegative integers reordered in groups of 5 even numbers followed by 5 odd numbers.

%H <a href="/index/Rec#order_11">Index entries for linear recurrences with constant coefficients</a>, signature (1, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1).

%F a(n)= g*10+2*r-9*floor(r/5), where g=floor(n/10) and r=n mod 10.

%F a(n)= a(n-10)+10.

%F O.g.f.: x(2+2x+2x^2+2x^3-7x^4+2x^5+2x^6+2x^7+2x^8+x^9)/( (-1+x)^2 (1+x)(x^4+x^3+x^2+x+1)(x^4-x^3+x^2-x+1)). - _R. J. Mathar_, Jul 22 2008

%t LinearRecurrence[{1,0,0,0,0,0,0,0,0,1,-1},{0,2,4,6,8,1,3,5,7,9,10},80] (* _Harvey P. Dale_, Jan 09 2017 *)

%t With[{nn=4},Riffle[Partition[Range[0,20nn,2],5],Partition[Range[1,20nn+1,2],5]]]// Flatten (* _Harvey P. Dale_, Mar 18 2023 *)

%Y Cf. A001477.

%K nonn,easy

%O 0,2

%A _Paul Curtz_, Oct 18 2007

%E Edited by _R. J. Mathar_, Jul 22 2008