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A108739
Mills' constant A generates a sequence of primes via b(n)= floor(A^3^n). This sequence is a(n) = b(n+1)-b(n)^3.
6
3, 30, 6, 80, 12, 450, 894, 3636, 70756, 97220, 66768, 300840, 1623568, 8436308
OFFSET
1,1
COMMENTS
This allows larger terms of A051254 (which triple in digits each entry) to be given. Like A051254, currently requires Riemann Hypothesis to show sequence continues.
Currently a(11)=66768 generates only a probable prime number. - Arkadiusz Wesolowski, May 28 2011
Likewise a(12) and a(13) generate only a probable prime numbers, as well as being conditional on a(11) and a(12) being proved primes. Minimality of a(12)-a(13) is exhaustively tested. - Serge Batalov, Aug 06 2013
a(14) = 8436308 is found by Ryan Propper and Serge Batalov, Apr 29 2024, but a few remaining gaps below this value were being double-checked. The double-check is now complete (see GitHub link). - Ryan Propper and Serge Batalov, May 24 2024.
REFERENCES
T. M. Apostol, Introduction to Analytic Number Theory, Springer-Verlag, 1976, page 8.
LINKS
Chris K. Caldwell, The List of Largest Known Primes, The 11th Mills' prime
Chris K. Caldwell and Yuanyou Cheng, Determining Mills' Constant and a Note on Honaker's Problem, Journal of Integer Sequences, Vol. 8 (2005), Article 05.4.1.
Henri & Renaud Lifchitz, PRP Records and PRP Records, search:Mills
W. H. Mills, A prime-representing function, Bull. Amer. Math. Soc., Vol. 53 (1947), p. 604.
Eric Weisstein's World of Mathematics, Mills' Constant
Eric Weisstein's World of Mathematics, Mills' Prime
E. M. Wright, A class of representing functions, J. London Math. Soc., Vol. 29 (1954) pp. 63-71.
FORMULA
b(1) = 2; b(n+1) = nextprime(b(n)^3); a(n) = b(n+1)-b(n)^3;
EXAMPLE
The Mills' primes (given in A051254) are 2, 2^3+3 = 11, (2^3+3)^3+30 = 11^3+30 = 1361, ((2^3+3)^3+30)^3+6 = 1361^3+6 = 2521008887, etc. The terms added at each step yield this sequence. They are the least positive integers which added to the cube of the preceding prime yield again a prime, cf. formula. - M. F. Hasler, Jul 22 2013
MATHEMATICA
B[1] = 2; B[n_] := B[n] = NextPrime[B[n - 1]^3]; Table[B[n + 1] - B[n]^3, {n, 7}] (* Robert Price, Jun 09 2019 *)
PROG
(PARI) p=2; until(, np=nextprime(p^3); print1(np-p^3, ", "); p=np) \\ Jeppe Stig Nielsen, Apr 22 2020
CROSSREFS
Sequence in context: A318971 A082792 A078242 * A072973 A154054 A118219
KEYWORD
more,nonn,hard
AUTHOR
Chris K. Caldwell, Jun 22 2005
EXTENSIONS
a(9)-a(11) from Caldwell and Cheng, Aug 29 2005
Corrected by T. D. Noe, Sep 24 2008
a(12) (which generates a PRP) from Serge Batalov, Jul 19 2013
a(13) (which generates a PRP) from Serge Batalov, Aug 06 2013
a(14) (which generates a PRP) from Ryan Propper and Serge Batalov, May 24 2024
STATUS
approved