login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A261970 Numbers whose base-b expansions, for both b=3 and b=4, include no digits other than 0 and b-1. 3

%I #51 Oct 13 2015 14:05:31

%S 0,60,240,13308,52992,53052,53196,3195132,3208140,3346188,12795648,

%T 12795900,871563264,871563312,871563456,871576368,871576380,871576524,

%U 871615728,871616268,871616448,1072939776,1072939788,1072939824,3225157884,3472949196,3473670912

%N Numbers whose base-b expansions, for both b=3 and b=4, include no digits other than 0 and b-1.

%H Paul Tek, <a href="/A261970/b261970.txt">Table of n, a(n) for n = 1..10000</a>

%H Paul Tek, <a href="/A261970/a261970.txt">PARI program for this sequence</a>

%e 60 is 2020 in base 3 and 330 in base 4; it uses the largest digits in the two bases (including 0's) and is therefore a term.

%e Similarly 240 is 22220 in base 3 and 3300 in base 4 so it is also a term.

%o (PARI) isokb(n, b) = {if (!n, return (1)); my(d = digits(n, b)); (#vecsort(d,,8)==2) && (vecmin(d) == 0) && (vecmax(d) == b - 1);}

%o isok(n) = isokb(n, 3) && isokb(n, 4); \\ _Michel Marcus_, Sep 22 2015

%Y Cf. A258981, A262958.

%K nonn,base

%O 1,2

%A _Robin Powell_, Sep 21 2015

%E More terms from _Alois P. Heinz_, Sep 21 2015

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 13 22:05 EDT 2024. Contains 375910 sequences. (Running on oeis4.)