A336143 Integers that are Brazilian and not Colombian.

8, 10, 12, 13, 14, 15, 16, 18, 21, 22, 24, 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 43, 44, 45, 46, 48, 50, 51, 52, 54, 55, 56, 57, 58, 60, 62, 63, 65, 66, 68, 69, 70, 72, 73, 74, 76, 77, 78, 80, 81, 82, 84, 85, 87, 88, 90, 91, 92, 93, 94, 95, 96, 98, 99, 100

Offset

1,1

Comments

There are no squares of primes in the data (all squares of primes are not Brazilian except for 121 that is Brazilian, but 121 is Colombian).

Links

Table of n, a(n) for n=1..67.

Giovanni Resta, Self or Colombian number, Numbers Aplenty.

Wikipédia, Nombre brésilien (in French).

Index to sequences related to Brazilian Numbers.

Index to sequences related to Colombian Numbers.

Example

15 is a term because 15 = 12 + (sum of digits of 12), so 15 is not Colombian and 15 = 33_4, so 15 is Brazilian.

Mathematica

brazQ[n_] := Module[{b = 2, found = False}, While[b < n - 1 && Length[Union[ IntegerDigits[n, b]]] > 1, b++]; b < n - 1]; n = 100; Select[Union@Table[Plus @@ IntegerDigits[k] + k, {k, 1, n}], # <= n && brazQ[#] &] (* Amiram Eldar, Jul 10 2020 *)

Crossrefs

Intersection of A125134 (Brazilian) and A176995 (not Colombian).

Cf. A003052 (Colombian), A333858 (Brazilian and Colombian), this sequence (Brazilian not Colombian), A336144 (Colombian not Brazilian).

Sequence in context: A102758 A176815 A338473 * A347267 A220571 A033872

Adjacent sequences: A336140 A336141 A336142 * A336144 A336145 A336146

Keyword

nonn,base

Author

Bernard Schott, Jul 10 2020

Status

approved