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A081880 Triangle read by rows: n-th row gives trajectory of 2n under the map x->(x^2-4)/6, stopping when the next term would be negative or nonintegral. 0
0, 2, 0, 4, 2, 0, 6, 8, 10, 16, 42, 10, 16, 42, 12, 14, 32, 170, 4816, 3865642, 2490531345360, 16, 42, 18, 20, 66, 22, 80, 1066, 189392, 5978221610, 5956522269711832016, 5913359591595499145281505571167104042, 5827970276585748074286667660065476529979312208145367609757859954142122960, 24, 26 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

LINKS

Pierre Abbat, The 64-100 Sequences

EXAMPLE

8 -> (64-4)/6 = 10 -> (100-4)/6 = 16 -> (256-4)/6 = 42 -> (42^2-4)/6 nonintegral, so stop; thus row 4 is (8, 10, 16, 42).

CROSSREFS

Sequence in context: A199891 A109468 A185879 * A144289 A037035 A159984

Adjacent sequences:  A081877 A081878 A081879 * A081881 A081882 A081883

KEYWORD

nonn,tabf

AUTHOR

Pierre Abbat, phma(AT)webjockey.net, Apr 12, 2003

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Last modified February 16 16:41 EST 2012. Contains 205938 sequences.