

A133311


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


0



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
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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*r9*floor(r/5), where g=floor(n/10) and r=n mod 10.
a(n)= a(n10)+10.
O.g.f.: x(2+2x+2x^2+2x^37x^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^4x^3+x^2x+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 *)


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



