A216432 Semiprimes that are sums of squares of two consecutive primes.

34, 74, 458, 4058, 28898, 45002, 51218, 57818, 64802, 84122, 115202, 145802, 233978, 352802, 363002, 530522, 609458, 649802, 756458, 924818, 994082, 1391162, 1609418, 2179922, 2599442, 2832218, 3328202, 3484802, 3864362, 3942482, 5425418, 5746058, 6125018

Offset

1,1

Comments

Semiprimes in A069484. - Zak Seidov, Apr 11 2014

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Example

34 = 2*17 = 3^2+5^2, 74 = 2*37 = 5^2+7^2, 458 = 2*229 = 13^2+17^2.

Mathematica

Select[(Total/@Partition[Prime[Range[500]]^2, 2, 1]), PrimeOmega[#]==2&] (* Harvey P. Dale, Sep 23 2012 *)

Prog

(PARI) v=List(); p=3; forprime(q=5, 1e4, if(isprime((p^2+q^2)\2), listput(v, p^2+q^2)); p=q); Vec(v) \\ Charles R Greathouse IV, Sep 23 2012

Crossrefs

Subsequence of A100484.

Cf. A000040, A001358, A069484.

Sequence in context: A184066 A277449 A063533 * A118619 A258413 A066944

Adjacent sequences: A216429 A216430 A216431 * A216433 A216434 A216435

Keyword

nonn

Author

Zak Seidov, Sep 09 2012

Status

approved