A261970 Numbers whose base-b expansions, for both b=3 and b=4, include no digits other than 0 and b-1.

0, 60, 240, 13308, 52992, 53052, 53196, 3195132, 3208140, 3346188, 12795648, 12795900, 871563264, 871563312, 871563456, 871576368, 871576380, 871576524, 871615728, 871616268, 871616448, 1072939776, 1072939788, 1072939824, 3225157884, 3472949196, 3473670912

Offset: 1

Author

Robin Powell, Sep 21 2015

Keywords

• nonn
• base

Examples

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

Links

• Paul Tek, Table of n, a(n) for n = 1..10000
• Paul Tek, PARI program for this sequence

Crossrefs

Cf. A258981, A262958.

Programs

PARI

isokb(n, b) = {if (!n, return (1)); my(d = digits(n, b)); (#vecsort(d,,8)==2) && (vecmin(d) == 0) && (vecmax(d) == b - 1);}
isok(n) = isokb(n, 3) && isokb(n, 4); \\ Michel Marcus, Sep 22 2015

Extensions

More terms from Alois P. Heinz, Sep 21 2015