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A062737 Primes p such that 4p-1 is also prime. 8
2, 3, 5, 11, 17, 41, 53, 71, 83, 131, 137, 173, 197, 227, 263, 281, 293, 383, 431, 467, 503, 521, 563, 587, 593, 617, 677, 683, 701, 743, 797, 827, 887, 911, 977, 983, 1013, 1061, 1091, 1151, 1163, 1181, 1277, 1307, 1361, 1481, 1511, 1523, 1553, 1607, 1613 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Solutions of the equation (4*n-1)'+n'=2, where n' is the arithmetic derivative of n. [Paolo P. Lava, Oct 31 2012]

For n>1, 4*a(n) is a solution to the equation phi(x-1) - phi(x) = x/2. - Farideh Firoozbakht, Dec 17 2014

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..1000

MAPLE

select(n -> isprime(n) and isprime(4*n-1), [2, seq(2*k+1, k=1..1000)]); # Robert Israel, Dec 17 2014

PROG

(PARI) { n=0; forprime (p=2, 10^5, if (isprime(4*p - 1), write("b062737.txt", n++, " ", p); if (n==1000, break)) ) } \\ Harry J. Smith, Aug 10 2009

CROSSREFS

Cf. A005384, A007700, A005382.

Sequence in context: A014210 A203074 A014556 * A085613 A082605 A007755

Adjacent sequences:  A062734 A062735 A062736 * A062738 A062739 A062740

KEYWORD

nonn,easy

AUTHOR

Reiner Martin (reinermartin(AT)hotmail.com), Jul 12 2001

STATUS

approved

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Last modified August 20 22:45 EDT 2019. Contains 326155 sequences. (Running on oeis4.)