A133311 The nonnegative integers reordered in groups of 5 even numbers followed by 5 odd numbers.

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, 23, 25, 27, 29, 30, 32, 34, 36, 38, 31, 33, 35, 37, 39, 40, 42, 44, 46, 48, 41, 43, 45, 47, 49, 50, 52, 54, 56, 58, 51, 53, 55, 57, 59, 60, 62, 64, 66, 68, 61, 63, 65, 67, 69, 70, 72, 74

Offset

0,2

Links

Table of n, a(n) for n=0..72.

Index entries for linear recurrences with constant coefficients, signature (1, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1).

Formula

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

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

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

Mathematica

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

Crossrefs

Cf. A001477.

Sequence in context: A169909 A180592 A004092 * A088402 A077492 A007396

Adjacent sequences: A133308 A133309 A133310 * A133312 A133313 A133314

Keyword

nonn,easy

Author

Paul Curtz, Oct 18 2007

Extensions

Edited by R. J. Mathar, Jul 22 2008

Status

approved