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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
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
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
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