

A288068


Repdigits in base 10 which are Brazilian numbers.


1



7, 8, 22, 33, 44, 55, 66, 77, 88, 99, 111, 222, 333, 444, 555, 666, 777, 888, 999, 1111, 2222, 3333, 4444, 5555, 6666, 7777, 8888, 9999, 11111, 22222, 33333, 44444, 55555, 66666, 77777, 88888, 99999, 111111, 222222, 333333, 444444, 555555, 666666, 777777, 888888, 999999
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

These numbers are all repdigits belonging to A010785. The representation of the numbers 7 and 8 in base 10 is not Brazilian but they are yet Brazilian because 7 = 111_2 and 8 = 22_3. Except the repdigits 7, 8, 22, 33, 55, 77 and the primes repunits R_n from A004022 and A004023, all these Brazilian repdigits are also Brazilian in another base.


LINKS

Table of n, a(n) for n=1..46.


EXAMPLE

7 = 111_2;
44 = 44_10 = 22_21;
66 = 66_10 = 33_21 = 22_32.


MATHEMATICA

Select[Flatten@ Table[FromDigits@ ConstantArray[k, n], {n, 6}, {k, 9}], Function[n, Length@ SelectFirst[Range[2, n  2], Count[DigitCount[n, #], _?(# > 0 &)] == 1 &] == 0]] (* Michael De Vlieger, Jun 06 2017, Version 10 *)


CROSSREFS

Cf. A004022, A004023, A010785, A014181, A125134,
Sequence in context: A051175 A322651 A325322 * A058537 A002362 A042417
Adjacent sequences: A288065 A288066 A288067 * A288069 A288070 A288071


KEYWORD

nonn,base


AUTHOR

Bernard Schott, Jun 05 2017


STATUS

approved



