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A104164 Sophie Germain type primes where 5*Prime[n]=2*Prime[m]+1. 1
7, 17, 47, 107, 167, 197, 257, 317, 347, 557, 677, 827, 947, 1097, 1217, 1307, 1367, 1427, 1607, 1847, 1877, 2027, 2207, 2267, 2297, 2417, 2477, 2657, 2927, 3257, 3557, 3617, 3677, 3917, 3947, 4157, 4397, 4457, 4877, 4967, 5507, 5717, 5867, 5927, 6257 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..45.

FORMULA

a(n) = If (5*Prime[n]-1)/2 is prime, then a[m]=(5*Prime[n]-1)/2

MATHEMATICA

a = Delete[Union[Table[If [PrimeQ[(5*Prime[n] - 1)/2] == True, (5*Prime[n] - 1)/2, 0], {n, 1, 1000}]], 1]

CROSSREFS

Cf. Sophie Germain primes: A005384.

Sequence in context: A107178 A061722 A195905 * A192244 A110097 A179262

Adjacent sequences:  A104161 A104162 A104163 * A104165 A104166 A104167

KEYWORD

nonn

AUTHOR

Roger L. Bagula, Mar 10 2005

STATUS

approved

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Last modified November 13 11:22 EST 2018. Contains 317133 sequences. (Running on oeis4.)