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 A117253 Column 0 of triangle A117252. 1
 1, 1, -3, 45, -2430, 433026, -245525742, 434685788658, -2376644549487615, 39849199161258840705, -2039314646436750180150939, 317469566015078743658568283029, -149970083228995077874358388356635368, 214577598849654850870918566871719460091160 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS FORMULA a(n) = [prod_{j=0..n-1} (1-3*j)]/n! * 3^(n*(n-1)/2). PROG (PARI) a(n)=prod(j=0, n-1, 1-3*j)/n!*3^(n*(n-1)/2) CROSSREFS Sequence in context: A154242 A283698 A163002 * A012833 A012747 A210933 Adjacent sequences:  A117250 A117251 A117252 * A117254 A117255 A117256 KEYWORD sign AUTHOR Paul D. Hanna, Mar 14 2006 STATUS approved

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