

A128928


Smallest member p of a triple of primes (p,p+8,p+20).


0



3, 11, 23, 53, 59, 89, 131, 173, 191, 263, 359, 389, 401, 479, 593, 599, 653, 719, 1013, 1031, 1109, 1193, 1229, 1283, 1439, 1451, 1523, 1559, 1601, 1733, 1979, 2273, 2531, 2663, 2699, 2711, 3041, 3209, 3251, 3299, 3323, 3449, 3491, 3539, 3623, 3719, 3911, 3923, 4091, 4211
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

A subsequence of A023202. The definition implies that the sum of the first two primes, 2(p+4), divides the sum of the product of the first two primes and the last, p(p+8)+p+20=(p+4)(p+5). This feature is shared with A022005 and common to prime triples of the format (p,p+2*a,p+a+a^2) with even a.  R. J. Mathar, Apr 26 2007


LINKS

Table of n, a(n) for n=1..50.


MAPLE

isA128928 := proc(n) isprime(n) and isprime(n+8) and isprime(n+20) ; end: for n from 1 to 300 do if isA128928(ithprime(n)) then printf("%d, ", ithprime(n)) ; fi ; od ; # R. J. Mathar, Apr 26 2007


MATHEMATICA

kmax = 580; Select[ Prime[ Range[1, kmax] ], (PrimeQ[ # + 8] && PrimeQ[ # + 20])& ] (* Stuart Clary *)


CROSSREFS

Cf. A022005.
Sequence in context: A335677 A248348 A173078 * A289888 A145477 A243887
Adjacent sequences: A128925 A128926 A128927 * A128929 A128930 A128931


KEYWORD

nonn


AUTHOR

J. M. Bergot, Apr 25 2007


EXTENSIONS

Corrected and extended by Robert G. Wilson v, R. J. Mathar and Stuart Clary, Apr 26 2007


STATUS

approved



