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A166088 Odd integers (that is, of the form 2n+1) for which Sum_{i=1..u} J(i,2n+1) obtains value zero exactly 8 times, when u ranges from 1 to (2n+1). Here J(i,k) is the Jacobi symbol. 1
29, 37, 41, 65, 73, 97, 177, 193 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Of these eight, all are of the form 4k+1, and all others are primes except 65 (= 5*13) and 177 (= 3*59). Conjecture: There are no more terms after the eight one, 193. (Checked up to the 400000th term of A166040, i.e. up to A005408(400000)=800001.)

LINKS

Table of n, a(n) for n=1..8.

PROG

(MIT Scheme with macro MATCHING-POS by AK):

(define (A166088 n) (A005408 (index_for_a166088 n)))

(define index_for_a166088 (MATCHING-POS 1 0 (lambda (i) (= 8 (A166040 i)))))

CROSSREFS

Sequence in context: A089297 A250291 A127956 * A295490 A172195 A161724

Adjacent sequences:  A166085 A166086 A166087 * A166089 A166090 A166091

KEYWORD

nonn

AUTHOR

Antti Karttunen, Oct 08 2009

STATUS

approved

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Last modified July 20 01:17 EDT 2019. Contains 325168 sequences. (Running on oeis4.)