login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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 (list; graph; refs; listen; history; text; internal format)
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 2-almost-primes) and A001358 (all 2-almost-primes).

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 4 07:59 EDT 2020. Contains 334822 sequences. (Running on oeis4.)