This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A109649 Entries in 3-dimensional version of Pascal triangle: trinomial coefficients. 7
 1, 1, 1, 1, 2, 1, 2, 2, 1, 1, 3, 3, 1, 3, 6, 3, 3, 3, 1, 1, 4, 6, 4, 1, 4, 12, 12, 4, 6, 12, 6, 4, 4, 1, 1, 5, 10, 10, 5, 1, 5, 20, 30, 20, 5, 10, 30, 30, 10, 10, 20, 10, 5, 5, 1, 1, 6, 15, 20, 15, 6, 1, 6, 30, 60, 60, 30, 6, 15, 60, 90, 60, 15, 20, 60, 60, 20, 15, 30, 15, 6 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS Greatest numbers in each 2D triangle form A022916 = (multinomial coefficient n!/([n/3]![(n+1)/3]![(n+2)/3]!). 2D triangle sums are powers of 3. See A046816 for another version. LINKS FORMULA Coefficients of x, y, z in (x+y+z)^n. EXAMPLE .1 3 3 1 ... Here is the third slice of the pyramid . 3 6 3 .. 3 3 ... 1 ..... CROSSREFS Cf. A007318, A046816, A002378, A027480, A033487, A033488. Sequence in context: A143786 A035176 A011793 * A098199 A022828 A129406 Adjacent sequences:  A109646 A109647 A109648 * A109650 A109651 A109652 KEYWORD nonn,tabf,easy AUTHOR Philippe DELEHAM, Aug 03 2005 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .