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A002502
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Number of connected relations.
(Formerly M5336 N2323)
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17
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1, 65, 1795, 36317, 636331, 10365005, 162470155, 2495037197, 37898120011, 572284920845, 8614868501515, 129467758660877, 1943971108806091, 29175170378428685, 437752102106036875, 6567275797761209357
(list;
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listen;
history;
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OFFSET
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1,2
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REFERENCES
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N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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FORMULA
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15^n-4*8^n-3*6^n+12*5^n-6*4^n. - Goran Kilibarda, Vladeta Jovovic, Apr 14 2004
G.f. x*( -1-27*x+136*x^2+480*x^3 ) / ( (6*x-1)*(5*x-1)*(15*x-1)*(4*x-1)*(8*x-1) ).
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MATHEMATICA
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LinearRecurrence[{38, -539, 3622, -11640, 14400}, {1, 65, 1795, 36317, 636331}, 20] (* Harvey P. Dale, Mar 24 2017 *)
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CROSSREFS
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KEYWORD
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nonn,nice,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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