login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A090570 Numbers that are congruent to {0, 1} mod 9. 8
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)). [Reinhard Zumkeller, Oct 10 2008]

LINKS

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

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

FORMULA

a(n) = 9*n-a(n-1)-17 (with a(1)=0). [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. - 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. - 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. [Reinhard Zumkeller, Oct 10 2008]

Sequence in context: A217935 A100595 A107433 * A131417 A268135 A058369

Adjacent sequences:  A090567 A090568 A090569 * A090571 A090572 A090573

KEYWORD

nonn,easy

AUTHOR

Giovanni Teofilatto, Feb 25 2004

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 2 19:13 EST 2016. Contains 278683 sequences.