A037807 - OEIS

%I #11 Jul 23 2023 18:24:48

%S 0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,0,0,0,1,1,1,1,1,1,0,0,0,0,1,1,1,1,

%T 1,0,0,0,0,0,1,1,1,1,0,0,0,0,0,0,1,1,1,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,

%U 0,0,1,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,0

%N Number of i such that d(i) < d(i-1), where Sum_{i=0..m} d(i)*9^i is the base-9 representation of n.

%p A037807 := proc(n)

%p     a := 0 ;

%p     dgs := convert(n,base,9);

%p     for i from 2 to nops(dgs) do

%p         if op(i,dgs)<op(i-1,dgs) then

%p             a := a+1 ;

%p         end if;

%p     end do:

%p     a ;

%p end proc: # _R. J. Mathar_, Oct 16 2015

%Y Cf. A037824.

%K nonn,base

%O 1,1

%A _Clark Kimberling_

%E Sign in name corrected by _R. J. Mathar_, Oct 16 2015