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A109769 Composite n such that binomial(7*n, n) == 7^n (mod n). +0
1
18, 25, 133, 2107, 4676, 226037, 4477739, 827867201 (list; graph; listen)
OFFSET

1,1

COMMENT

No other terms below 10^9.

LINKS

Max Alekseyev, PARI/GP scripts for various problems

EXAMPLE

18 is a term because binomial(7*18, 18) = 2797093093529137508875, 7^18 = 1628413597910449 and 2797093093529137508875 mod 18 = 1628413597910449 mod 18 = 1.

MATHEMATICA

Do[If[ !PrimeQ[n], If[Mod[Binomial[7*n, n], n] == Mod[7^n, n], Print[n]]], {n, 2, 20000}]

CROSSREFS

Cf. A080469.

Sequence in context: A072422 A003300 A084379 this_sequence A093018 A167336 A003634

Adjacent sequences: A109766 A109767 A109768 this_sequence A109770 A109771 A109772

KEYWORD

more,nonn,new

AUTHOR

Ryan Propper (rpropper(AT)stanford.edu), Aug 13 2005

EXTENSIONS

226037 from Max Alekseyev (maxale(AT)gmail.com), Sep 13 2009

Two more terms from Max Alekseyev (maxale(AT)gmail.com), Nov 06 2009

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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