A146981 Numbers k of the form q^2, q = prime, such that k-2 is a prime.

4, 9, 25, 49, 169, 361, 841, 1369, 1849, 2209, 3721, 5041, 7921, 10609, 11449, 16129, 17161, 19321, 29929, 36481, 44521, 49729, 54289, 57121, 66049, 85849, 97969, 113569, 128881, 177241, 196249, 201601, 218089, 241081, 273529, 292681, 323761

Offset

1,1

Comments

Except for initial term, a(n) - 1 is not a squarefree number.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = A049002(n) + 2.

a(n) = A062326(n)^2. - Amiram Eldar, Oct 21 2019

Mathematica

Select[Prime[Range[150]]^2, PrimeQ[#-2]&] (* Harvey P. Dale, Jan 15 2020 *)

Crossrefs

Cf. A049002, A062326.

Sequence in context: A376746 A326708 A028866 * A068373 A030481 A160190

Adjacent sequences: A146978 A146979 A146980 * A146982 A146983 A146984

Keyword

nonn

Author

Giovanni Teofilatto, Nov 04 2008

Extensions

Corrected (3721 inserted, 10321 replaced by 19321, 49729 and 218089 inserted) by R. J. Mathar, Apr 22 2010

Status

approved