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A051256
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Numbers formed from binomial coefficients (mod 2) interpreted as digits in factorial base.
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3
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1, 3, 7, 33, 121, 843, 5167, 46233, 362881, 3991683, 40279687, 522910113, 6227383801, 93409304523, 1313941673647, 22324392524313, 355687428096001, 6758061133824003, 122000787836928007, 2561305169719296033
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| a(n) = Sum (k+1)!(C(n, k) mod 2), k=0..n
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EXAMPLE
| a(5) = 1!+2!+5!+6! = 843 (Only the first, second, fifth and sixth terms are odd at the row 5 of Pascal's Triangle).
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MAPLE
| A051256(n) := proc(n) local i; RETURN(add(((binomial(n, i) mod 2)*((i+1)!)), i=0..n)); end;
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CROSSREFS
| Cf. A001317, A001339, A048757, A047999.
Sequence in context: A007646 A120566 A057480 * A057795 A054935 A024496
Adjacent sequences: A051253 A051254 A051255 * A051257 A051258 A051259
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KEYWORD
| nonn,nice
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AUTHOR
| Antti Karttunen Oct 24 1999
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