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A080474 a(n)= product of sum of taking (n-1) numbers from the next n numbers. The next n numbers can be grouped like this (1), (2,3), (4,5,6), (7,8,9,10),... . Let N be the sum of all the members of the n-th group. Let k be a member and f(k) = N - k. Then a(n) = the product of all f(k) for k taking all member values. 1
1, 6, 990, 421200, 379501200, 625757605200, 1707530790369600, 7172573016426048000, 43928207579534870592000, 376055676152225153019936000, 4350748615258091511751558272000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..11.

EXAMPLE

a(3)= 990. The third group of next n numbers is (4,5,6) and a(3) = (4+5)*(5+6)*(4+6)= 990.

CROSSREFS

Cf. A080473.

Sequence in context: A250392 A145250 A024085 * A079190 A203303 A159865

Adjacent sequences:  A080471 A080472 A080473 * A080475 A080476 A080477

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Mar 11 2003

EXTENSIONS

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 06 2003

STATUS

approved

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Last modified October 22 04:25 EDT 2019. Contains 328315 sequences. (Running on oeis4.)