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

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A017629 a(n) = 12*n+9. 16
9, 21, 33, 45, 57, 69, 81, 93, 105, 117, 129, 141, 153, 165, 177, 189, 201, 213, 225, 237, 249, 261, 273, 285, 297, 309, 321, 333, 345, 357, 369, 381, 393, 405, 417, 429, 441, 453, 465, 477, 489, 501, 513, 525, 537, 549, 561, 573, 585, 597, 609, 621, 633 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Numbers k such that k mod 2 = (k+1) mod 3 = 1 and (k+2) mod 4 <> 1. - Klaus Brockhaus, Jun 15 2004

For n>3, the number of squares on the infinite 3-column chessboard at <=n knight moves from any fixed point. - Ralf Stephan, Sep 15 2004

A089911(2*a(n)) = 4. - Reinhard Zumkeller, Jul 05 2013

LINKS

Table of n, a(n) for n=0..52.

Tanya Khovanova, Recursive Sequences

Index entries for linear recurrences with constant coefficients, signature (2,-1).

FORMULA

a(n) = 6*(4n+1)-a(n-1) (with a(0)=9). - Vincenzo Librandi, Dec 17 2010

MATHEMATICA

12*Range[0, 200]+9 (* Vladimir Joseph Stephan Orlovsky, Feb 19 2011*)

PROG

(Sage) [i+9 for i in range(525) if gcd(i, 12) == 12] # - Zerinvary Lajos, May 21 2009

(Haskell)

a017629 = (+ 9) . (* 12)  -- Reinhard Zumkeller, Jul 05 2013

(PARI) a(n)=12*n+9 \\ Charles R Greathouse IV, Jul 10 2016

CROSSREFS

Cf. A008594, A017533, A017545.

Subsequence of A072065.

Cf. A017137, A004767.

Sequence in context: A133929 A086470 A176256 * A216240 A176258 A107978

Adjacent sequences:  A017626 A017627 A017628 * A017630 A017631 A017632

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

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 November 19 16:10 EST 2017. Contains 294936 sequences.