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A166088
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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.
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1
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OFFSET
| 1,1
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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.)
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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)))))
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CROSSREFS
| Sequence in context: A089296 A089297 A127956 * A172195 A161724 A046502
Adjacent sequences: A166085 A166086 A166087 * A166089 A166090 A166091
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KEYWORD
| nonn
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AUTHOR
| Antti Karttunen (His-Firstname.His-Surname(AT)gmail.com), Oct 08 2009
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