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A333858 Numbers that are both Colombian and Brazilian. 3
7, 20, 31, 42, 64, 75, 86, 108, 110, 121, 132, 143, 154, 165, 176, 187, 198, 209, 211, 222, 244, 255, 266, 288, 299, 310, 312, 323, 334, 345, 356, 378, 400, 411, 413, 424, 435, 446, 468, 490, 501, 512, 514, 525, 536, 558, 580, 591, 602, 615, 626, 637, 648, 670, 681, 692 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

121 is the only square of prime in this sequence.

LINKS

Table of n, a(n) for n=1..56.

Wikipédia, Nombre brésilien (in French).

Index entries for sequences related to Brazilian Numbers.

Index entries for sequences related to Colombian Numbers.

EXAMPLE

20 is a term because it is not of the form m + sum of digits of m for any m < 20, so 20 is Colombian and 20 = (22)_9, so 20 is also Brazilian.

MATHEMATICA

brazQ[n_] := Module[{b = 2, found = False}, While[b < n - 1 && Length[Union[IntegerDigits[n, b]]] > 1, b++]; b < n - 1]; n = 700; Select[Complement[Range[n], Union @ Table[Plus @@ IntegerDigits[k] + k, {k, 1, n}]], brazQ] (* Amiram Eldar, Apr 08 2020 after T. D. Noe at A125134 *)

CROSSREFS

Intersection of A003052 and A125134.

Sequence in context: A055069 A134863 A214924 * A319966 A200773 A269044

Adjacent sequences:  A333855 A333856 A333857 * A333859 A333860 A333861

KEYWORD

nonn,base

AUTHOR

Bernard Schott, Apr 08 2020

STATUS

approved

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Last modified May 17 23:07 EDT 2022. Contains 353779 sequences. (Running on oeis4.)