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A033168
Longest arithmetic progression of primes with difference 210 and minimal initial term.
3
199, 409, 619, 829, 1039, 1249, 1459, 1669, 1879, 2089
OFFSET
0,1
COMMENTS
Since 210 == 1 (mod 11), a progression of primes with difference 210 can't have more than ten terms because there is exactly one multiple of 11 within each run of eleven consecutive terms. For example, 2089 + 210 = 2299 = 11^2 * 19. - Alonso del Arte, Dec 22 2017, edited by M. F. Hasler, Jan 02 2020
After 199, the next prime which starts a CPAP-10 with common gap 210 is 243051733. See A094220 for further starting points. - M. F. Hasler, Jan 02 2020
REFERENCES
Paul Glendinning, Math in Minutes: 200 Key Concepts Explained in an Instant. New York, London: Quercus (2013): pp. 316-317.
David Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, Revised edition 1987. See p. 143.
FORMULA
a(n) = a(0) + n*210 for 0 <= n <= 9. - M. F. Hasler, Jan 02 2020
MATHEMATICA
199 + 210*Range[0, 9] (* Paolo Xausa, Sep 14 2024 *)
PROG
(PARI) forprime(p=1, , for(i=1, 9, isprime(p+i*210)||next(2)); return([p+d|d<-[0..9]*210])) \\ M. F. Hasler, Jan 02 2020
CROSSREFS
Cf. A094220.
Sequence in context: A004926 A004946 A157955 * A227283 A269325 A227284
KEYWORD
nonn,fini,full
AUTHOR
Manuel Valdivia, Apr 22 1998
STATUS
approved