login
A124588
Primes p such that q - p <= 2, where q is the next prime after p.
7
2, 3, 5, 11, 17, 29, 41, 59, 71, 101, 107, 137, 149, 179, 191, 197, 227, 239, 269, 281, 311, 347, 419, 431, 461, 521, 569, 599, 617, 641, 659, 809, 821, 827, 857, 881, 1019, 1031, 1049, 1061, 1091, 1151, 1229, 1277, 1289, 1301, 1319, 1427, 1451, 1481, 1487, 1607
OFFSET
1,1
COMMENTS
Consists of 2 together with the lower members of twin primes, A001359. See the latter entry for references.
"Assuming certain (admittedly difficult) conjectures on the distribution of primes in arithmetic progressions, [Goldston-Pintz-Yildirim] prove the existence of infinitely many prime pairs that differ at most by 16." - Soundararajan
Lesser of twin primes together with 2; union with A029710 gives A124589. - Reinhard Zumkeller, Dec 23 2006
Primes p such that either p + 3/2 +- 1/2 is prime. - Juri-Stepan Gerasimov, Jan 29 2010
The prime differences of 2 primes (without repetition). - Juri-Stepan Gerasimov, Jun 01 2010, Jun 08 2010
Numbers k such that sigma(k*(k+2)) = (k+1)*(k+3). - Wesley Ivan Hurt, May 08 2022
MATHEMATICA
Transpose[Select[Partition[Prime[Range[300]], 2, 1], #[[2]]-#[[1]]<3&]] [[1]] (* Harvey P. Dale, Feb 11 2015 *)
PROG
(PARI) twinl(n) = { c=0; x=1; while(c<n, if(isprime(prime(x)+2), c++); x++; ); return(prime(x-1)) }
print1(2", "); (for(x=1, 200, print1(twinl(x)", "))) \\ Cino Hilliard, Mar 29 2008
CROSSREFS
Cf. A001359.
Sequence in context: A038909 A073534 A063091 * A059428 A084571 A345471
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 19 2006; edited May 15 2008 at the suggestion of R. J. Mathar
STATUS
approved