A352837 Primes p such that, if q is the next prime, p + q^2 is a prime times a power of 10.

2, 409, 709, 1249, 3229, 4621, 6709, 7069, 7129, 7489, 8209, 9241, 9661, 10789, 11149, 13381, 13789, 15349, 17509, 20641, 21169, 21961, 23509, 25819, 26449, 28309, 28729, 32029, 32089, 34849, 35089, 35809, 37321, 37369, 39769, 40129, 42169, 42349, 42709, 42901, 42979, 44179, 46489, 47269, 47809

Offset

1,1

Comments

Primes prime(k) such that when any trailing zeros are removed from A349660(k), the result is prime.

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(3) = 709 is a term because 709 and 719 are consecutive primes, 709 + 719^2 = 517670, and 51767 is prime.

Maple

R:= NULL: count:= 0:
q:= 2:
while count < 100 do
  p:= q; q:= nextprime(p);
  v:= p+q^2;
  if v mod 10 = 0 then v:= v/10^min(padic:-ordp(v, 2), padic:-ordp(v, 5)) fi;
  if isprime(v) then count:= count+1; R:= R, p; fi;
od:
R;

Mathematica

f[n_] := n/10^IntegerExponent[n, 10]; Select[Range[50000], PrimeQ[#] && PrimeQ[f[# + NextPrime[#]^2]] &] (* Amiram Eldar, Apr 07 2022 *)

Crossrefs

Cf. A349660, A352848.

Sequence in context: A283661 A067827 A070269 * A352848 A349764 A153911

Adjacent sequences: A352834 A352835 A352836 * A352838 A352839 A352840

Keyword

nonn

Author

J. M. Bergot and Robert Israel, Apr 05 2022

Status

approved