A191404 - OEIS

%I #11 Aug 10 2022 03:05:14

%S 4,7,11,13,17,20,23,27,29,33,37,39,43,46,49,53,55,59,62,65,69,71,75,

%T 79,81,85,88,91,95,97,101,105,107,111,114,117,121,123,127,130,133,137,

%U 139,143,147,149,153,156,159,163,165,169,172,175,179,181,185,189,191,195,198,201,205,207,211,215,217,221,224,227

%N a(n) = A000201(n) + A000201(n+3).

%C See A191402.

%t (See A191402.)

%o (Python)

%o from math import isqrt

%o def A191404(n): return (n+isqrt(m:=5*n**2)>>1)+(n+3+isqrt(m+30*n+45)>>1) # _Chai Wah Wu_, Aug 10 2022

%Y Cf. A000201, A191402.

%K nonn

%O 0,1

%A _Clark Kimberling_, Jun 01 2011