A080390 - OEIS

%I #11 Oct 26 2019 22:26:19

%S 1,5,14,27,34,11,62,183,98,39,142,107,220,69,44,495,322,143,436,139,

%T 482,637,574,119,674,233,782,55,898,29,1146,4063,230,441,174,467,1516,

%U 493,662,239,1762,377,2020,175,764,781,2302,2543,2596,949,968,207,3126,1241

%N Least x such that gcd(A001405(x+1), A001405(x)) = n.

%F a(n) = Min{x; A057977(x)=n}.

%t f[x_] := GCD[Binomial[x+1, Floor[x+1/2]], Binomial[x, Floor[x/2]]] t=Table[0, {257}]; Do[s=f[n]; If[s<258&&t[[s]]==0, t[[s]]=n], {n, 1, 10000}]; t

%Y Cf. A001405, A057977, A080389.

%K nonn

%O 1,2

%A _Labos Elemer_, Mar 12 2003