This site is supported by donations to The OEIS Foundation.

The October issue of the Notices of the Amer. Math. Soc. has an article about the OEIS.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A005905 Number of points on surface of truncated tetrahedron: 14n^2 + 2 for n>0, a(0)=1. (Formerly M5001) 2
 1, 16, 58, 128, 226, 352, 506, 688, 898, 1136, 1402, 1696, 2018, 2368, 2746, 3152, 3586, 4048, 4538, 5056, 5602, 6176, 6778, 7408, 8066, 8752, 9466, 10208, 10978, 11776, 12602, 13456, 14338, 15248, 16186, 17152, 18146, 19168, 20218, 21296, 22402, 23536, 24698 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Also sequence found by reading the segment (1, 16) together with the line from 16, in the direction 16, 58,..., in the square spiral whose vertices are the generalized enneagonal numbers A118277. - Omar E. Pol, Nov 05 2012 REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS H. S. M. Coxeter, Polyhedral Numbers, in R. S. Cohen et al., editors, For Dirk Struik. Reidel, Dordrecht, 1974, pp. 25-35. Simon Plouffe, Approximations de séries génératrices et quelques conjectures, Dissertation, Université du Québec à Montréal, 1992. Simon Plouffe, 1031 Generating Functions and Conjectures, Université du Québec à Montréal, 1992. B. K. Teo and N. J. A. Sloane, Magic numbers in polygonal and polyhedral clusters, Inorgan. Chem. 24 (1985),4545-4558. MAPLE A005905:=-(z+1)*(z**2+12*z+1)/(z-1)**3; # [Simon Plouffe in his 1992 dissertation.] MATHEMATICA a[0] = 1; a[n_] := 14 n^2 + 2; Table[a[n], {n, 0, 50}] (* Wesley Ivan Hurt, Mar 04 2014 *) PROG (PARI) a(n) = if (n==0, 1, 14*n^2+2); \\ Michel Marcus, Mar 04 2014 CROSSREFS Cf. A206399. Sequence in context: A235736 A235517 A253428 * A177890 A225922 A235510 Adjacent sequences:  A005902 A005903 A005904 * A005906 A005907 A005908 KEYWORD nonn,easy AUTHOR EXTENSIONS More terms from Michel Marcus, Mar 04 2014 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.

Last modified September 24 22:27 EDT 2018. Contains 315360 sequences. (Running on oeis4.)