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A145741 Numbers p such that p + 4*m^2 is prime for m = 0,1,2,3,...,10. 9
163, 409333, 1867783, 828497443, 2059599067, 5767711867, 8965599883, 9655686727, 9671300983, 12627473917, 19635778453, 31428255373, 76292280733, 140192390683, 141077258953, 141805795657, 150360096973, 176552953273, 186521536807, 250298387047 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
It is obvious that all terms are prime.
A very strange and interesting thing related to the first term: All 20 numbers 163+4*m^2 for m=0,1,2,...,19 are prime.
There are 3136 terms below 10^15, ending with 999926956948957. - Jens Kruse Andersen, Oct 24 2008
LINKS
Carlos Rivera, Puzzle 464. p+4*x^2.
EXAMPLE
All 11 numbers 2059599067 + 4*m^2 for m = 0,1,2,...,10 are prime, so 2059599067 is a term.
PROG
(PARI) forprime(p=1, 5*10^8, c=0; for(m=1, 10, if(!isprime(p+4*m^2), break); c+=1); if(c==10, print1(p, ", "))) \\ Derek Orr, Jul 25 2017
CROSSREFS
Sequence in context: A146504 A306501 A247269 * A247273 A247275 A247276
KEYWORD
nonn
AUTHOR
Farideh Firoozbakht, Oct 17 2008
EXTENSIONS
More terms from Jens Kruse Andersen, Oct 24 2008
STATUS
approved

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Last modified May 10 10:55 EDT 2024. Contains 372377 sequences. (Running on oeis4.)