A176788 a(n) = (0!! + 1!! + 2!! + 3!! + ... + (n-1)!!) mod n.

0, 0, 1, 3, 0, 0, 1, 7, 0, 2, 6, 3, 12, 10, 12, 3, 13, 6, 11, 7, 3, 8, 14, 15, 12, 22, 15, 3, 19, 12, 16, 11, 30, 14, 17, 15, 17, 34, 9, 7, 26, 24, 36, 19, 42, 8, 2, 3, 24, 12, 48, 35, 2, 42, 52, 31, 15, 22, 51, 27, 32, 56, 24, 27, 22, 30, 6, 31, 54, 52, 12, 15, 7, 56, 12, 15, 52, 48

Offset

1,4

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Formula

a(n) = A129981(n-1) mod n.

Example

0!! mod 1 = 1 mod 1 = 0.
(0!!+1!!) mod 2 = (1 + 1) mod 2 = 0.
(0!!+1!!+2!!) mod 3 = (1 + 1 + 2) mod 3 = 1.

Maple

A176788 := proc(n)
        A129981(n-1) mod n ;
end proc: # R. J. Mathar, Jul 13 2012

Mathematica

Table[Mod[Total[Range[0, n-1]!!], n], {n, 80}] (* Harvey P. Dale, Nov 15 2021 *)

Crossrefs

Cf. A049782, A176787, A176789.

Sequence in context: A080159 A144299 A060514 * A350450 A238129 A344118

Adjacent sequences: A176785 A176786 A176787 * A176789 A176790 A176791

Keyword

easy,nonn

Author

Paolo P. Lava & Giorgio Balzarotti, Apr 26 2010

Status

approved