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 A176650 Numbers k such that nonnegative non-semiprime(k)+3 = nonnegative non-semiprime(k+3). 1
 1, 11, 12, 18, 19, 20, 26, 27, 28, 47, 53, 63, 64, 65, 66, 67, 68, 69, 73, 83, 84, 91, 92, 93, 98, 99, 100, 101, 102, 109, 115, 116, 117, 118, 122, 128, 129, 130, 134, 135, 136, 148, 152, 153, 154, 155, 156, 161, 162, 163, 164, 165, 166, 174, 183, 184, 185, 192, 193 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Where nonnegative non-semiprime numbers are zero together with A100959 (i.e., 0, 1, 2, 3, 5, 7, 8, 11, 12, 13, 16, 17, 18, 19, 20, 23, 24, 27, 28, 29, 30, ...). LINKS Jinyuan Wang, Table of n, a(n) for n = 1..10000 EXAMPLE 1 is a term because nonnegative non-semiprime(1)+3 = 3 = nonnegative non-semiprime(1+3). MAPLE A100959 := proc(n) option remember; if n = 1 then 1; else for a from procname(n-1)+1 do if numtheory[bigomega](a) <> 2 then return a; end if; end do end if; end proc: nnnspr := proc(n) if n = 1 then 0; else A100959(n-1) ; end if; end proc: isA176650 := proc(n) nnnspr(n) + 3 = nnnspr(n+3) ; end proc: for n from 1 to 1200 do if isA176650(n) then printf("%d, ", n) ; end if; end do: # R. J. Mathar, Apr 26 2010 CROSSREFS Cf. A100959 (non-semiprimes). Sequence in context: A079350 A070605 A087450 * A046465 A134926 A105744 Adjacent sequences:  A176647 A176648 A176649 * A176651 A176652 A176653 KEYWORD nonn AUTHOR Juri-Stepan Gerasimov, Apr 22 2010 EXTENSIONS Entries checked by R. J. Mathar, Apr 26 2010 STATUS approved

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Last modified May 13 19:36 EDT 2021. Contains 343868 sequences. (Running on oeis4.)