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 A146948 Semiprimes n such that n+1 and n+2 are squarefree. 1
 4, 9, 21, 33, 57, 65, 69, 77, 85, 93, 121, 129, 141, 177, 185, 201, 209, 213, 217, 221, 237, 253, 265, 289, 301, 309, 321, 329, 365, 381, 393, 417, 437, 445, 453, 469, 481, 497, 501, 517, 533, 545, 553, 581, 589, 597, 633, 669, 681, 689, 697, 713, 717, 753 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Terms computed by Zak Seidov. Except 4, all terms == 1 (mod 4). - Robert Israel, May 14 2020 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 MAPLE filter:= n -> numtheory:-bigomega(n)=2 and numtheory:-issqrfree(n+1) and numtheory:-issqrfree(n+2): select(filter, [4, seq(i, i=5..1000, 4)]); # Robert Israel, May 14 2020 MATHEMATICA Select[Range[800], PrimeOmega[#]==2&&And@@SquareFreeQ/@(#+{1, 2})&] (* Harvey P. Dale, Oct 30 2013 *) CROSSREFS Sequence in context: A290434 A230834 A120535 * A033944 A287143 A238641 Adjacent sequences: A146945 A146946 A146947 * A146949 A146950 A146951 KEYWORD nonn,less AUTHOR Giovanni Teofilatto, Nov 03 2008 STATUS approved

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Last modified February 29 20:48 EST 2024. Contains 370428 sequences. (Running on oeis4.)