A308983 - OEIS

%I #21 Oct 04 2019 09:09:42

%S 4,15,18,20,23,29,33,34,35,36,38,39,43,48,49,50,54,56,60,62,63,66,68,

%T 69,74,75,77,78,81,83,84,86,88,89

%N Numbers n such that A308803(2n+1) = (2*10^n-1)(5*10^n+1).

%C A308803(2n+1) >= (2*10^n-1)(5*10^n+1) for all n. This sequence lists the values of n where this lower bound is attained.

%Y Cf. A308803

%K nonn,base,more

%O 1,1

%A _Chai Wah Wu_, Sep 30 2019

%E a(14)-a(34) from _Chai Wah Wu_, Oct 03 2019