login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A088198 Distance LQnR(p_n) (A088196) from p_n. 7
1, 2, 1, 1, 2, 3, 1, 1, 2, 1, 2, 3, 1, 1, 2, 1, 2, 1, 1, 5, 1, 1, 3, 5, 2, 1, 1, 2, 3, 1, 1, 3, 1, 2, 1, 2, 1, 1, 2, 1, 2, 1, 5, 2, 1, 1, 1, 1, 2, 3, 1, 7, 1, 3, 1, 2, 1, 2, 3, 1, 2, 1, 1, 5, 2, 1, 5, 1, 2, 3, 1, 1, 2, 1, 1, 2, 2, 3, 7, 1, 2, 1, 5, 1, 1, 3, 5, 2, 1, 1, 1, 1, 1, 1, 1, 2, 3, 1, 2 (list; graph; refs; listen; history; internal format)
OFFSET

2,2

COMMENTS

The members of the sequence are either 1's or primes (easily provable)

LINKS

Ferenc Adorjan, The sequence of largest quadratic residues modulo the primes.

FORMULA

a(n)=p(n)-LQnR(p(n)), where p(n) is the n-th prime and LQnR(x) is the lagest quadratic non-residue modulo x.

PROG

(PARI) qnrp_pm(fr, n)= {/* The the distance of primes from the largest QnR modulo the primes */ local(m, p, fl, jj, j, v=[]); fr=max(fr, 2); for(i=fr, n, m=0; p=prime(i); jj=0; fl=2^p-1; j=2; while((j<=(p-1)/2), jj=(j^2)%p; fl-=2^jj; j++); j=p-1; while(m==0, if(bitand(2^j, fl), m=j); j--); v=concat(v, p-m)); print(v)}

CROSSREFS

Cf. A088192, A088196, A088197, A088199, A088200, A088201.

Sequence in context: A116361 A106796 A082850 * A088426 A124769 A128227

Adjacent sequences:  A088195 A088196 A088197 * A088199 A088200 A088201

KEYWORD

easy,nonn

AUTHOR

Ferenc Adorjan (fadorjan(AT)freemail.hu), Sep 23 2003

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 10:57 EST 2012. Contains 206009 sequences.