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%I #12 Mar 07 2023 09:21:53
%S 1,9,16,25,53,78,82,89,115,120,130,152,161,178,196,224,233,235,250,
%T 256,265,286,291,300,301,314,315,325,347,357,360,368,381,391,397,419,
%U 428,430,456,468,479,483,484,494,495,512,528,570,577,589,591,608,610,620
%N Terms which occur at least twice in A161182.
%C A161182 is not monotonic, so some terms (like 89) listed here are not direct neighbors in A161182. - _R. J. Mathar_, Jun 22 2009
%p A038107 := proc(n) numtheory[pi]( n^2) ; end: A078435 := proc(n) n^2-A038107(n) ; end: A161182 := proc(n) A078435(n)-A078435(n-1) ; end: L := [] ; for n from 1 to 1200 do L := [op(L), A161182(n)] ; od: read("transforms3") ; L := sort(L) ; L := LISTDUPL(L,0) ; # _R. J. Mathar_, Jun 22 2009
%t f[n_] := 2n - 1 - PrimePi[n^2] + PrimePi[(n-1)^2];
%t Select[Split[Array[f, 1000]//Sort], Length[#] >= 2&][[All, 1]]
%t (* _Jean-François Alcover_, Mar 07 2023 *)
%Y Cf. A078435, A161182.
%K easy,nonn
%O 1,2
%A _Daniel Tisdale_, Jun 05 2009
%E Edited by _N. J. A. Sloane_, Jun 07 2009
%E Missing numbers added by _R. J. Mathar_, Jun 22 2009
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