%I
%S 1,3930,6044,61879,137256
%N n is equal to the number of 1's in all numbers <= n written in base 7.
%t Module[{nn=137300,dc},dc=Accumulate[DigitCount[Range[nn],7,1]];Position[ Thread[ {Range[nn],dc}],_?(#[[1]]==#[[2]]&),1,Heads> False]]//Flatten (* _Harvey P. Dale_, Oct 10 2021 *)
%Y Cf. A014778, A014886.
%K nonn,base,fini,full
%O 1,2
%A _Olivier GĂ©rard_
%E List proved complete by _Hugo van der Sanden_ (cf. A014886).
