A279688 -id:A279688 - cp's OEIS frontend

A279916 Least b such that A279688(n) and 2*A279688(n) are anagrams in base b.

5, 4, 8, 4, 3, 5, 5, 14, 4, 4, 4, 3, 3, 3, 4, 3, 4, 4, 4, 4, 20, 8, 23, 8, 11, 5, 5, 26, 5, 3, 3, 3, 4, 3, 4, 29, 3, 3, 3, 4, 3, 3, 4, 3, 4, 32, 6, 4, 11, 4, 4, 4, 35, 4, 4, 11, 4, 4, 4, 4, 4, 7, 38, 4, 6, 4, 4, 4, 4, 8, 41, 11, 16, 8, 44, 3, 47, 3, 3, 3, 3, 3

Offset: 2

Peter Kagey, Dec 23 2016

			A279688(2) = 8, and a(2) = 5 because 5 is the least base such that 8 and 16 are anagrams: 8 = 13_5 and 16 = 31_5.

Peter Kagey, Table of n, a(n) for n = 2..10000

Cf. A023094, A279688, A279689.

DeleteCases[#, 0] &@ Table[Module[{b = 2}, While[2 b < n + 3 && Sort[IntegerDigits[n, b]] != Sort[IntegerDigits[2 n, b]], b++]; b Boole[2 b < n + 3]], {n, 780}] (* Michael De Vlieger, Dec 23 2016, after Robert G. Wilson v at A279688 *)

A279689 Numbers n such that n and 2n are anagrams in more than one base.

Original entry on oeis.org

0, 40, 96, 104, 208, 248, 258, 288, 312, 480, 752, 833, 936, 960, 968, 1170, 1248, 1728, 1755, 2090, 2232, 2400, 2608, 2768, 2808, 2832, 2904, 4224, 4464, 5208, 5280, 5418, 6075, 6584, 6696, 6714, 6720, 6768, 6800, 6966, 7020, 7182, 7200, 7714, 7728, 7776

Offset: 1

Peter Kagey, Dec 17 2016

			a(2) = 40 because 40 and 80 are anagrams in bases 5 and 11.
a(13) = 936 because 936 and 1872 are anagrams in bases 3, 9, and 53.

Chai Wah Wu, Table of n, a(n) for n = 1..1001

Cf. A279688.

isok(n) = (n==0) || sum(b=2, n, vecsort(digits(n,b)) == vecsort(digits(2*n,b))) > 1; \\ Michel Marcus, Dec 17 2016

cp's OEIS Frontend

A279916 Least b such that A279688(n) and 2*A279688(n) are anagrams in base b.

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