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%I #10 Mar 03 2020 12:11:40
%S 1,15,20,28,17,19,44,52,29,31,68,76,41,43,92,49,51,53,55,116,124,65,
%T 67,69,71,148,77,79,164,172,89,91,188,97,99,101,103,212,109,111,113,
%U 115,236,244,125,127,129,131,268,137,139,284,292,149,151,153,155,316,161,163,332
%N First differences of A161753.
%H G. C. Greubel, <a href="/A163602/b163602.txt">Table of n, a(n) for n = 1..5000</a>
%F a(n) = A161753(n+1) - A161753(n).
%e a(1)=1=1^2-0^2. a(2)=15=4^2-1^2. a(3)=20=6^2-4^2.
%p A141468 := proc(n) if n <= 2 then n-1 ; else for a from procname(n-1)+1 do if not isprime(a) then RETURN(a) ; fi; od: fi; end;
%p A161753 := proc(n) A141468(n)^2 ; end:
%p A163602 := proc(n) A161753(n+1)-A161753(n) ; end: seq(A163602(n),n=1..100) ; # _R. J. Mathar_, Aug 07 2009
%t A161753 := With[{nn = 500}, Complement[Range[0, nn], Prime[Range[PrimePi[nn]]]]^2]; Table[A161753[[n + 1]] - A161753[[n]], {n, 1, 50}] (* _G. C. Greubel_, Jul 29 2017 *)
%t Differences[With[{nn=100},Complement[Range[0,nn],Prime[Range[ PrimePi[ nn]]]]^2]] (* _Harvey P. Dale_, Mar 03 2020 *)
%Y Cf. A001248, A141468, A161753.
%K nonn,easy
%O 1,2
%A _Juri-Stepan Gerasimov_, Aug 01 2009
%E a(6) corrected by _R. J. Mathar_, Aug 07 2009
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