A071782 Sum of distinct squares in Z_n (mod n).

0, 1, 1, 1, 0, 2, 0, 5, 3, 5, 0, 2, 0, 0, 0, 14, 0, 6, 0, 15, 7, 0, 0, 18, 0, 13, 18, 0, 0, 0, 0, 8, 0, 17, 0, 24, 0, 0, 13, 15, 0, 14, 0, 22, 0, 0, 0, 28, 0, 25, 0, 39, 0, 9, 0, 28, 19, 29, 0, 30, 0, 0, 21, 32, 0, 0, 0, 17, 0, 0, 0, 36, 0, 37, 50, 38, 0, 26, 0, 10

Offset

1,6

Comments

a(n)=0 for prime n>3. - T. D. Noe, Sep 06 2005

Links

Antti Karttunen, Table of n, a(n) for n = 1..16848

Mathematica

a[n_] := Mod[Apply[Plus, Union[Table[Mod[i^2, n], {i, 1, n}]]], n]

Prog

(PARI) A071782(n) = (vecsum(Set(vector(n, i, (i^2)%n)))%n); \\ Antti Karttunen, Feb 18 2023

Crossrefs

Sequence in context: A021491 A324654 A121705 * A328495 A297024 A356215

Adjacent sequences: A071779 A071780 A071781 * A071783 A071784 A071785

Keyword

nonn

Author

Santi Spadaro, Jun 24 2002

Status

approved