id:A109649 - OEIS Search Results

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Entries in 3-dimensional version of Pascal triangle: trinomial coefficients.

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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; listen)

	OFFSET	`0,5`
	COMMENT	`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.`
	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 this_sequence A098199 A022828 A129406` `Adjacent sequences: A109646 A109647 A109648 this_sequence A109650 A109651 A109652`
	KEYWORD	`nonn,tabf,easy`
	AUTHOR	`Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Aug 03 2005`

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Last modified December 5 08:23 EST 2009. Contains 170348 sequences.

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