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A076410 (Sum of the quadratic residues of prime(n)) / prime(n). 9
1, 1, 2, 3, 4, 4, 4, 7, 6, 9, 10, 10, 9, 13, 13, 15, 16, 14, 18, 17, 19, 22, 24, 25, 23, 25, 27, 28, 29, 30, 34, 33, 37, 34, 39, 40, 36, 43, 42, 45, 41, 48, 49, 45, 51, 52, 54, 57, 58, 52, 60, 59, 64, 59, 67, 62, 69, 70, 69, 73, 75, 68, 78, 79, 81, 84, 84, 87, 88, 80, 87, 93, 93 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,3

COMMENTS

Always an integer for primes > 3.

REFERENCES

Kenneth A. Ribet, Modular forms and Diophantine questions, Challenges for the 21st century (Singapore 2000), 162-182; World Sci. Publishing, River Edge NJ 2001; Math. Rev. 2002i:11030.

LINKS

Table of n, a(n) for n=3..75.

FORMULA

a(n) = A076409(n)/prime(n).

a(n) ~= p(n)/4. - David W. Wilson, Oct 09 2002

If prime(n) = 4k+1 then a(n) = k.

MATHEMATICA

Table[ Apply[ Plus, Flatten[ Position[ Table[ JacobiSymbol[i, Prime[n]], {i, 1, Prime[n] - 1}], 1]]] /Prime[n], {n, 3, 50}]

CROSSREFS

Sequence in context: A114212 A108355 A057951 * A211509 A058277 A065852

Adjacent sequences:  A076407 A076408 A076409 * A076411 A076412 A076413

KEYWORD

nonn

AUTHOR

R. K. Guy, Oct 08 2002

EXTENSIONS

Edited and extended by Robert G. Wilson v, Oct 09 2002

STATUS

approved

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Last modified November 22 05:36 EST 2017. Contains 295076 sequences.