

A074931


Primes p such that 3p is equidistant from consecutive prime twin pairs.


0



3, 5, 17, 29, 41, 71, 149, 281, 317, 347, 359, 397, 647, 751, 787, 857, 907, 1093, 1279, 1381, 1511, 1531, 1663, 1783, 2447, 2683, 2803, 3271, 3323, 4019, 4153, 4513, 4567, 4639, 5557, 5647, 5801, 5923, 6599, 6659, 6911, 7013, 7573, 7883, 9187, 9257, 9431
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OFFSET

1,1


COMMENTS

Numbers equidistant from consecutive twins (see A074953) are multiples of 3 and they may be almost primes only of form 3*prime. In the sequence, these primes are given. Also: A001748 (3*prime 2almostprimes) and A001358 (all 2almostprimes).


LINKS

Table of n, a(n) for n=1..47.


EXAMPLE

17 is in the sequence because 3 * 17 = 51 is equidistant between {41, 43} and {59, 61}.
19 is not in the sequence because 3 * 19 = 57, which is much closer to {59, 61} than to {41, 43}.


CROSSREFS

Cf. A001358, A001748, A074953.
Sequence in context: A038703 A283806 A163586 * A023226 A113169 A174913
Adjacent sequences: A074928 A074929 A074930 * A074932 A074933 A074934


KEYWORD

nonn


AUTHOR

N. Fernandez (primeness(AT)borve.org), Zak Seidov, Oct 10 2002


EXTENSIONS

New name from Charles R Greathouse IV, Oct 12 2013


STATUS

approved



