This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A194713 13 times hexagonal numbers: 13*n*(2*n-1). 1
 0, 13, 78, 195, 364, 585, 858, 1183, 1560, 1989, 2470, 3003, 3588, 4225, 4914, 5655, 6448, 7293, 8190, 9139, 10140, 11193, 12298, 13455, 14664, 15925, 17238, 18603, 20020, 21489, 23010, 24583, 26208, 27885, 29614, 31395, 33228, 35113, 37050, 39039 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Sequence found by reading the line from 0, in the direction 0, 13, ..., in the square spiral whose vertices are the generalized 15-gonal numbers. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..10000 Index entries for linear recurrences with constant coefficients, signature (3,-3,1). FORMULA a(n) = 26*n^2 - 13*n = 13*A000384(n). a(n) = a(n-1) + 52*n - 39, a(0)=0. - Vincenzo Librandi, Oct 03 2011 PROG (MAGMA) [13*n*(2*n-1): n in [0..50]]; // Vincenzo Librandi, Oct 03 2011 (PARI) a(n)=13*n*(2*n-1) \\ Charles R Greathouse IV, Jun 17 2017 CROSSREFS Cf. A000384, A002939, A094159, A152745, A195320, A154617, A143698. Sequence in context: A126423 A072474 A186103 * A047638 A010929 A022608 Adjacent sequences:  A194710 A194711 A194712 * A194714 A194715 A194716 KEYWORD nonn,easy AUTHOR Omar E. Pol, Oct 02 2011 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 September 15 20:11 EDT 2019. Contains 327086 sequences. (Running on oeis4.)