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A090570 Numbers that are congruent to {0, 1} mod 9. 4
0, 1, 9, 10, 18, 19, 27, 28, 36, 37, 45, 46, 54, 55, 63, 64, 72, 73, 81, 82, 90, 91, 99, 100, 108, 109, 117, 118, 126, 127, 135, 136, 144, 145, 153, 154, 162, 163, 171, 172, 180, 181, 189, 190, 198, 199, 207, 208, 216, 217, 225, 226 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

A145389(a(n)) = A010888(a(n)). [From Reinhard Zumkeller, Oct 10 2008]

LINKS

Table of n, a(n) for n=1..52.

Index to sequences with linear recurrences with constant coefficients, signature (1,1,-1).

FORMULA

a(n)=9*n-a(n-1)-17 (with a(1)=0) [From Vincenzo Librandi, Nov 16 2010]

a(n) = 9*n/2 -25/4 -7*(-1)^n/4. G.f.  x^2*(1+8*x)  / ( (1+x)*(x-1)^2 ). - R. J. Mathar, Oct 08 2011

a(n+1)=Sum_k>=0 {A030308(n,k)*A005010(k-1)}, with A005010(-1)=1. - From Philippe Deléham, Oct 17 2011.

EXAMPLE

13 is 1101 in base 2, so a(13+1)=a(14)=36*1+18*1+9*0+1*1=36+18+1=55. - From Philippe Deléham, Oct 17 2011.

MAPLE

a[0]:=0:a[1]:=1:for n from 2 to 100 do a[n]:=a[n-2]+9 od: seq(a[n], n=0..51); - Zerinvary Lajos, Mar 16 2008

PROG

(PARI) forstep(n=0, 200, [1, 8], print1(n", ")) \\ Charles R Greathouse IV, Oct 17 2011

CROSSREFS

Union of A008591 and A017173. [From Reinhard Zumkeller, Oct 10 2008]

Sequence in context: A217935 A100595 A107433 * A131417 A058369 A110939

Adjacent sequences:  A090567 A090568 A090569 * A090571 A090572 A090573

KEYWORD

nonn,easy

AUTHOR

Giovanni Teofilatto, Feb 25 2004

STATUS

approved

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Last modified October 26 02:56 EDT 2014. Contains 248566 sequences.