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A202607 Numbers n such that 6n and sigma(6n) are both a twin prime average. 0
1, 5, 77, 177, 215, 247, 313, 348, 465, 593, 712, 723, 1092, 1110, 1218, 1335, 1433, 1470, 1673, 1738, 1755, 1815, 1990, 2007, 2153, 2223, 2293, 2830, 2903, 2930, 3042, 3332, 3598, 3673, 3790, 3957, 4308, 4477, 4623, 5338, 5548, 5955, 6258, 6297, 7030, 7095 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..46.

EXAMPLE

a(4)=177 because 6*177-1=1061, 6*177+1=1063, A000203(6*177)-1=2339 and A000203(6*177)+1=2341 are all primes.

PROG

(PARI) for(n=1, 1e4, if(isprime(6*n-1)&&isprime(6*n+1)&&isprime(sigma(6*n)-1)&&isprime(sigma(6*n)+1), print1(n", "))) \\ Charles R Greathouse IV, Dec 26 2011

CROSSREFS

Cf. A000203, A014574, A193687.

Sequence in context: A088756 A319186 A076215 * A222533 A059856 A001513

Adjacent sequences:  A202604 A202605 A202606 * A202608 A202609 A202610

KEYWORD

nonn,less

AUTHOR

Juri-Stepan Gerasimov, Dec 21 2011

STATUS

approved

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Last modified November 18 12:16 EST 2019. Contains 329261 sequences. (Running on oeis4.)