cp's OEIS Frontend

A045816 Number of times the digits are repeated in A045815.

%I A045816 #25 Nov 12 2022 06:20:04
%S A045816 1,1,1,1,1,1,1,1,1,4,8,4,2,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
%T A045816 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
%U A045816 3,3,3,3,3,3,3,3,3,3,3,3,3,6
%N A045816 Number of times the digits are repeated in A045815.
%H A045816 Naohiro Nomoto, <a href="https://web.archive.org/web/20000916012426/http://www.geocities.co.jp/Technopolis/1793/09digit.htm">In the list of divisors of n,... </a>
%e A045816 Divisors of 20345 are (1,20345), the numbers of digits are [0(1),1(1),2(1),3(1),4(1),5(1)], so a(1) = 1.
%e A045816 Divisors of 45050 are (1,2,3,10,4505,13414,22323,45050), the numbers of digits (0-5) are [0(4),1(4),2(4),3(4),4(4),5(4)], so a(10) = 4.
%p A045816 isA045816 := proc(n) local c,j,b,h,a ; a := [0,0,0,0,0,0] : c := numtheory[divisors](n): for j from 1 to nops(c) do b := convert(c[j], base, 6); for h from 1 to nops(b) do a[b[h]+1] := a[b[h]+1]+1: end do: end do: if(a[1]=a[2] and a[2]=a[3] and a[3]=a[4] and a[4]=a[5] and a[5]=a[6]) then a[1] ; else -1 ; end if: end: n := 1: while true do a := isA045816(n) : if a >= 0 then printf("%d, ",a) ; fi ; n := n+1 : od : # _R. J. Mathar_, Jun 26 2007
%Y A045816 Cf. A038564, A038565.
%K A045816 easy,nonn,base
%O A045816 1,10
%A A045816 _Naohiro Nomoto_
%E A045816 More terms from _Sean A. Irvine_, Sep 26 2011