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A204904 p(n)-q(n), where (p(n), q(n)) is the least pair of odd primes for which n divides p(n)-q(n). 1
2, 2, 6, 4, 10, 6, 14, 8, 18, 10, 22, 12, 26, 14, 30, 16, 34, 18, 38, 20, 42, 22, 46, 24, 50, 26, 54, 28, 58, 30, 62, 32, 66, 34, 70, 36, 74, 38, 78, 40, 82, 42, 86, 44, 90, 46, 94, 48, 98, 50, 102, 52, 106, 54, 110, 56, 114, 58, 118, 60, 122, 62, 126, 64, 130 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This sequence agrees with A109043 for 0<n<=65; what about all larger n?

For a guide to related sequences, see A204892.

Sequence agrees with A109043 at least up to 6400. - Michel Marcus, Mar 14 2018

If Polignac's conjecture is true, then this is a duplicate of A109043. - Robert Israel, Mar 14 2018

LINKS

Table of n, a(n) for n=1..65.

Wikipedia, Polignac's conjecture

EXAMPLE

1 = (5-3)/2=(7-3)/4=(13-3)/6=(11-3)/8=...

2 = (5-3)/1=(11-5)/3=(7-3)/5=(17-3)/7=...

MATHEMATICA

(See the program at A204900.)

PROG

(PARI) a(n) = {forprime(p=5, , forprime(q=3, p-1, d = p-q; if ((d % n) == 0, return (d)); ); ); } \\ Michel Marcus, Mar 14 2018

CROSSREFS

Cf. A066043, A109043, A204900, A204892, A210530.

Sequence in context: A053213 A292258 A140524 * A109043 A054585 A278236

Adjacent sequences:  A204901 A204902 A204903 * A204905 A204906 A204907

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jan 20 2012

STATUS

approved

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Last modified September 26 22:11 EDT 2022. Contains 357051 sequences. (Running on oeis4.)