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A065397
Primes which have no representation p + k*(k+1) / 2, with p prime and k > 0: A000040-Complement of A065396.
5
2, 7, 61, 211
OFFSET
1,1
COMMENTS
Finite? (Checked up to A000040(100000) = 1299709.)
Next term > 7000000. - R. J. Mathar, Apr 23 2006
No other terms less than 2*10^9. - T. D. Noe, Mar 26 2008
MAPLE
for n from 1 to 7000000 do if isprime(n) = true then foundp := false ; for k from 1 to n do if isprime(n-k*(k+1)/2) = true then foundp := true ; break ; elif n-k*(k+1)/2 < 2 then break ; fi ; od ; if foundp = false then print(n) ; fi ; fi ; od : # R. J. Mathar, Apr 23 2006
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Reinhard Zumkeller, Nov 05 2001
STATUS
approved