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A253776
Primes representable as x^y + x + y, where x>1, y>1 are integers.
4
13, 71, 137, 251, 353, 523, 1013, 1033, 2213, 4933, 24421, 32803, 39341, 59063, 78137, 117701, 125053, 140663, 148933, 205441, 274693, 279949, 343073, 371311, 456613, 493121, 524309, 571873, 681563, 912773, 1225153, 1594339, 1953253, 2406241, 2924353, 3241943, 3652421
OFFSET
1,1
LINKS
Robert Israel and Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 (first 800 terms from Israel)
MAPLE
N:= 10^6; # to get all terms <= N
A:= select(t -> t <= N and isprime(t), {seq(seq(x^y+x+y, y = 2..floor(log[x](N-x))), x=2..floor(sqrt(N)))}, N):
sort(convert(A, list)); # Robert Israel, Sep 18 2024
PROG
(PARI) list(lim)=my(v=List()); forstep(y=3, oo, 2, if(2^y+y+2>lim, break); for(x=2, oo, my(p=x^y+x+y); if(p>lim, break); if(isprime(p), listput(v, p)))); Set(v) \\ Charles R Greathouse IV, Sep 18 2024
CROSSREFS
Sequence in context: A066831 A067382 A340842 * A158941 A128003 A060103
KEYWORD
nonn
AUTHOR
Alex Ratushnyak, Jan 12 2015
STATUS
approved