The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A001538 a(n) = (12n+1)*(12n+11). 6
 11, 299, 875, 1739, 2891, 4331, 6059, 8075, 10379, 12971, 15851, 19019, 22475, 26219, 30251, 34571, 39179, 44075, 49259, 54731, 60491, 66539, 72875, 79499, 86411, 93611, 101099, 108875, 116939, 125291, 133931, 142859, 152075, 161579, 171371, 181451, 191819 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS T. D. Noe, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (3,-3,1). FORMULA a(n) = (9 * A001533(n) - 19)/4. a(n) = 288*n + a(n-1) with a(0)=11. - Vincenzo Librandi, Nov 12 2010 G.f.: -(11 + 266*x + 11*x^2)/(x-1)^3 . - R. J. Mathar, Jun 30 2020 From Amiram Eldar, Feb 20 2023: (Start) a(n) = A017533(n)*A017653(n). Sum_{n>=0} 1/a(n) = (sqrt(3)+2)*Pi/120. Sum_{n>=0} (-1)^n/a(n) = (4*log(sqrt(2)+1) + sqrt(3)*log(5+2*sqrt(6)))/(60*sqrt(2)). Product_{n>=0} (1 - 1/a(n)) = (2*sqrt(2)/(sqrt(3)-1))*cos(sqrt(13/2)*Pi/6). Product_{n>=0} (1 + 1/a(n)) = 2*sqrt(2+sqrt(3))*cos(Pi/sqrt(6)). (End) PROG (PARI) a(n)=(12*n+1)*(12*n+11) \\ Charles R Greathouse IV, Jun 16 2017 CROSSREFS Cf. A001533, A017533, A017653. Sequence in context: A165390 A213256 A067424 * A101269 A012184 A012027 Adjacent sequences: A001535 A001536 A001537 * A001539 A001540 A001541 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 26 15:54 EDT 2023. Contains 365660 sequences. (Running on oeis4.)