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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

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Last modified September 28 05:33 EDT 2020. Contains 337392 sequences. (Running on oeis4.)