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%I #9 Jan 22 2019 02:48:39
%S 0,1,4,8,12,18,24,32,40,49,60,72,84,98,112,128,144,161,180,200,220,
%T 242,264,287,312,338,364,391,420,450,480,511,543,576,610,645,681,718,
%U 756,795,835,876,918,961,1005,1050,1096,1143,1191,1240,1290,1341,1393,1446
%N a(1)=0, a(n+1) is smallest nonprime >= a(n)+n.
%H Harvey P. Dale, <a href="/A156324/b156324.txt">Table of n, a(n) for n = 1..1000</a>
%e a(4) is the smallest nonprime >= a(3) + 3 = 4 + 3 = 7, hence a(4)=8.
%p A141468 := proc(n) option remember ; local a ; if n = 1 then 0 ; else for a from procname(n-1)+1 do if not isprime(a) then RETURN(a) ; fi; od: fi; end: A156324 := proc(n) option remember ; local a; if n = 1 then 0; else for a from procname(n-1)+n-1 do if not isprime(a) then RETURN(a) ; fi; od: fi; end: seq(A156324(n),n=1..80) ; # _R. J. Mathar_, Feb 10 2009
%t nxt[{n_,a_}]:=Module[{k=0,c=a+n+1},While[PrimeQ[c+k],k++];{n+1,c+k}]; Transpose[NestList[nxt,{0,0},60]][[2]] (* _Harvey P. Dale_, Dec 29 2015 *)
%Y Cf. A000040, A055496, A141468.
%K nonn
%O 1,3
%A _Juri-Stepan Gerasimov_, Feb 08 2009
%E Terms beginning at a(31) corrected by _R. J. Mathar_, Feb 10 2009