cp's OEIS Frontend

A183298 Complement of A147875.

%I A183298 #10 Oct 12 2024 16:37:32
%S A183298 1,2,3,5,6,7,8,9,10,11,12,14,15,16,17,18,19,20,21,22,23,24,25,26,28,
%T A183298 29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,47,48,49,50,51,52,
%U A183298 53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85
%N A183298 Complement of A147875.
%F A183298 (See the Mathematica code.)
%F A183298 a(n) = n+floor(sqrt(2n/5)) if 2n > floor(sqrt(2n/5))(5*floor(sqrt(2n/5))+1) and a(n) = n+floor(sqrt(2n/5))-1 otherwise. - _Chai Wah Wu_, Oct 12 2024
%t A183298 a=5/2; b=3/2;
%t A183298 F[n_]:=a*n^2+b*n;
%t A183298 R[n_]:=(n/a+((b-1)/(2a))^2)^(1/2);
%t A183298 G[n_]:=n-1+Ceiling[R[n]-(b-1)/(2a)];
%t A183298 Table[F[n], {n,60}]
%t A183298 Table[G[n], {n,100}]
%o A183298 (Python)
%o A183298 from math import isqrt
%o A183298 def A183298(n): return n+(m:=isqrt((k:=n<<1)//5))-(k<=m*(5*m+1)) # _Chai Wah Wu_, Oct 12 2024
%Y A183298 Cf. A147875.
%K A183298 nonn
%O A183298 1,2
%A A183298 _Clark Kimberling_, Jan 03 2011