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A061007 -(n-1)! mod n. 8
0, 1, 1, 2, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0 (list; graph; refs; listen; history; internal format)
OFFSET

1,4

COMMENTS

The following sequences all appear to have the same parity (with an extra zero term at the start of A010051): A010051, A061007, A035026, A069754, A071574. - Jeremy Gardiner (jeremy.gardiner(AT)btinternet.com), Aug 09, 2002

FORMULA

a(4)=2, a(p)=1 for p prime, a(n)=0 otherwise. Apart from n=4, a(n)=A010051(n)=A061006(n)/(n-1).

EXAMPLE

a(4)=2 since -(4-1)!=-6=2 mod 4. a(5)=1 since (5-1)!=-24=1 mod 5. a(6)=0 since -(6-1)!=-120=0 mod 6.

MAPLE

P=proc(n) local a, i, k, w; print(0); for i from 0 by 1 to n do w:=(i! mod (i+2)); print(w); od; end: P(1000); - Paolo P. Lava (paoloplava(AT)gmail.com), Apr 23 2007

CROSSREFS

Positive for all but the first term of A046022. Cf. A000040, A000142, A061006, A061008, A061009.

Sequence in context: A025439 A116852 A060154 * A206567 A085252 A073423

Adjacent sequences:  A061004 A061005 A061006 * A061008 A061009 A061010

KEYWORD

nonn

AUTHOR

Henry Bottomley (se16(AT)btinternet.com), Apr 12 2001

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Last modified February 15 16:56 EST 2012. Contains 205825 sequences.