OFFSET
1,1
REFERENCES
Crandall and Pomerance, "Prime numbers, a computational perspective", p. 69, Research Problem 1.75.
LINKS
C. Rivera, Problem 42
C. Rivera, Puzzle 227
Eric Weisstein's World of Mathematics, Power Floor Prime Sequence
EXAMPLE
a(1)=8 because for x=111/47 the sequence [x^k], k=1,2,... 2,5,13,31,73,173,409,967,... starts with 8 primes and this is the maximum for any x with [x]=2. (Compare also A063636, though the rational number x = 1287/545 used there is not of minimal height!)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Johann Wiesenbauer (j.wiesenbauer(AT)tuwien.ac.at), May 02 2004
EXTENSIONS
a(22) = 46 from Johann Wiesenbauer (j.wiesenbauer(AT)tuwien.ac.at), Jun 03 2004
a(23) = 49 from Johann Wiesenbauer (j.wiesenbauer(AT)tuwien.ac.at), Jun 27 2004
a(24) = 51 from Johann Wiesenbauer (j.wiesenbauer(AT)tuwien.ac.at), Aug 08 2004
a(25) and a(26) from Michael Kenn (michael.kenn(AT)philips.com), Jan 03 2006, who says: To achieve this result I used a shared network of 37 computers over the Christmas holidays. The total calculation time was equivalent to slightly more than 1 CPU year of a P4 - 2.4GHz.
STATUS
approved