The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A139609 a(n) = 36*n + 9. 3
 9, 45, 81, 117, 153, 189, 225, 261, 297, 333, 369, 405, 441, 477, 513, 549, 585, 621, 657, 693, 729, 765, 801, 837, 873, 909, 945, 981, 1017, 1053, 1089, 1125, 1161, 1197, 1233, 1269, 1305, 1341, 1377, 1413, 1449, 1485, 1521, 1557, 1593, 1629, 1665, 1701 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Numbers of the 9th column of positive numbers in the square array of nonnegative and polygonal numbers A139600. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..5000 Index entries for linear recurrences with constant coefficients, signature (2,-1). FORMULA a(n) = A057145(n+2,9). G.f.: 9*(1+3*x)/(x-1)^2. - R. J. Mathar, Jul 28 2016 MATHEMATICA Range[9, 7000, 36] (* Vladimir Joseph Stephan Orlovsky, Jul 23 2011 *) 36*Range[0, 50]+9 (* or *) LinearRecurrence[{2, -1}, {9, 45}, 50] (* Harvey P. Dale, Jan 04 2018 *) PROG (MAGMA) [9*(4*n + 1): n in [0..60]]; // Vincenzo Librandi, Jul 23 2011 (PARI) a(n)=36*n+9 \\ Charles R Greathouse IV, Oct 05 2011 CROSSREFS Sequence in context: A207359 A243090 A067536 * A321779 A068314 A152996 Adjacent sequences:  A139606 A139607 A139608 * A139610 A139611 A139612 KEYWORD easy,nonn AUTHOR Omar E. Pol, Apr 27 2008 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified July 28 10:29 EDT 2021. Contains 346326 sequences. (Running on oeis4.)