**Tetrahedral (or triangular pyramidal) numbers: a(n) = C(n+2,3) = n*(n+1)*(n+2)/6.**

*0, 1, 4, 10, 20, 35, 56, 84, 120, 165, 220, 286, 364, 455, 560, 680, 816, 969, 1140*

Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword

*11 seqfan posts*

*Sun Dec 25 22:24:29 CET 2011* [seqfan] Merry Christmas (M3382 and keyword:cons)

*Mon Dec 19 07:09:30 CET 2011* [seqfan] Update on triangle related to A050446.

*Tue Dec 6 08:57:23 CET 2011* [seqfan] A new triangle revisited

*Fri Oct 29 05:35:16 CEST 2010* [seqfan] Implementing first 500 sequences in Java

*Fri Jul 30 17:42:43 CEST 2010* [seqfan] Re: Number of n-digit numbers the binary expansion of which contains k runs of 1's

*Fri Jul 30 16:31:05 CEST 2010* [seqfan] Re: Number of n-digit numbers the binary expansion of which contains k runs of 1's

*Fri Jul 30 16:08:09 CEST 2010* [seqfan] Number of n-digit binary numbers containing k runs of 1's

*Fri Jul 30 15:51:13 CEST 2010* [seqfan] Number of n-digit numbers the binary expansion of which contains k runs of 1's

*Fri Jun 4 18:01:20 CEST 2010* [seqfan] Re: 3D version of A000938: 3-in-line inside the nXnXn cube

*Thu Apr 23 21:29:22 CEST 2009* [seqfan] Re: Offsets for Recurrence Sequences

*Mon Jan 12 11:27:00 CET 2009* [seqfan] Re: Index of linear recurrences

Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword

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