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A112630
Squares of the form 3S + 4, where S is a semiprime.
0
16, 49, 121, 169, 289, 361, 961, 1225, 1681, 2401, 3025, 3481, 5041, 7225, 8281, 9025, 11881, 15625, 19321, 25921, 30625, 32041, 32761, 39601, 48841, 55225, 57121, 70225, 72361, 93025, 96721, 101761, 108241
OFFSET
1,1
MATHEMATICA
Select[Select[Range[50000], PrimeOmega[#]==2&]*3+4, IntegerQ[Sqrt[#]]&] (* James C. McMahon, Jun 05 2024 *)
PROG
(PARI) select(issquare, apply(x->3*x+4, select(x->(bigomega(x)==2), [1..100000]))) \\ Michel Marcus, Jun 15 2024
CROSSREFS
Subsequence of A000290.
Cf. A001358.
Sequence in context: A016778 A009952 A105823 * A039606 A041498 A264479
KEYWORD
nonn
AUTHOR
Giovanni Teofilatto, Dec 22 2005
EXTENSIONS
Extended beyond 289 by R. J. Mathar, Jun 28 2010
STATUS
approved