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A210185
Sum of distinct residues of all factorials mod prime(n).
2
1, 3, 7, 12, 24, 56, 97, 103, 156, 224, 341, 494, 608, 521, 732, 821, 997, 1412, 1312, 1228, 1592, 1984, 2212, 2503, 2583, 3158, 3644, 3846, 3309, 4004, 5149, 5394, 6214, 6129, 7667, 6371, 8100, 8320, 8464, 9174, 10195, 10083, 11973, 11660, 12174, 11530, 14053
OFFSET
1,2
LINKS
EXAMPLE
Let n=4, p_4=7. We have modulo 7: 1!==1, 2!==2, 3!==6, 4!==3, 5!==1, 6!==6 and for m>=7, m!==0, such that we have 5 distinct residues 0,1,2,3,6. Therefore a(4)=0+1+2+3+6=12.
MATHEMATICA
Table[Total[Union[Mod[Range[Prime[n]]!, Prime[n]]]], {n, 100}] (* T. D. Noe, Mar 18 2012 *)
PROG
(PARI) a(n) = my(p=prime(n)); vecsum(Set(vector(p, k, k! % p))); \\ Michel Marcus, Dec 15 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Mar 18 2012
STATUS
approved