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Search: id:A051306
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| A051306 |
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Number of 6-element proper antichains of an n-element set. |
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+0
2
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| 0, 0, 0, 0, 0, 300, 233821, 78501094, 15532759830, 2213672795040, 254206334062527, 25146386270836578, 2235664320306737320, 183782806231396191820, 14248056393984957136593
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OFFSET
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0,6
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FORMULA
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1/6! (64^n -45*48^n +300*40^n -135*36^n +510*34^n -198*33^n -1499*32^n -2700*30^n +6615*28^n +1215*27^n -780*26^n +3750*25^n -6750*24^n -8280*23^n +3828*22^n -12285*21^n +19425*20^n +31635*19^n -30105*18^n -34425*17^n +24770*16^n +13125*15^n -3885*14^n +390*13^n -5670*12^n -12485*11^n +28575*10^n -16560*9^n -3435*8^n +7868*7^n -4995*6^n +3800*5^n -1301*4^n -822*3^n +668*2^n -120)
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CROSSREFS
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Cf. A032263, A036239, A051112.
Sequence in context: A036517 A063935 A015275 this_sequence A151609 A004225 A004226
Adjacent sequences: A051303 A051304 A051305 this_sequence A051307 A051308 A051309
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KEYWORD
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nonn
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AUTHOR
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Vladeta Jovovic, Goran Kilibarda, Zoran Maksimovic (vladeta(AT)eunet.rs)
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