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A165683 Primes of form 3*p*(p-1)+1 with p also a prime. 2
7, 19, 61, 127, 331, 2437, 2791, 5419, 8269, 10267, 13267, 23497, 35317, 55897, 73477, 89269, 115837, 170647, 292969, 360187, 372769, 452797, 603457, 812761, 895987, 929077, 976411, 997057, 1074607, 1125469, 1253887, 1372957, 1609669, 1653919 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

FORMULA

a(n) = x^3-(x-1)^3 where x = A165682(n).

EXAMPLE

a(3)= 61=3*5*(5-1)+1 generated by p=3. a(4)=127=3*7*(7-1)+1 generated by p=7. a(5)=331=3*11*(11-1)+1.

CROSSREFS

Cf. A165681, A165682

Sequence in context: A155335 A155226 A179406 * A092359 A155338 A155401

Adjacent sequences:  A165680 A165681 A165682 * A165684 A165685 A165686

KEYWORD

nonn

AUTHOR

Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Sep 24 2009

EXTENSIONS

7 and 19 inserted by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 26 2009

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Last modified February 16 21:51 EST 2012. Contains 205978 sequences.