A231931 Terms of A231930 written in base 10: the binary expansions of a(n) and a(n+1) taken together can be rearranged to form a palindrome.

0, 9, 1, 8, 64, 10, 2, 16, 65, 18, 3, 11, 25, 67, 24, 72, 27, 4, 12, 33, 68, 32, 76, 20, 34, 74, 17, 66, 80, 129, 136, 512, 69, 13, 5, 21, 42, 77, 29, 43, 75, 19, 26, 81, 22, 6, 14, 49, 70, 48, 78, 30, 51, 89, 28, 35, 92, 99, 204, 225, 267, 281, 515, 73, 15, 7, 23, 58

Offset

0,2

Comments

See A231930 for precise definition.

This is a permutation of the nonnegative integers - see the Comments in A228407 for the proof.

Links

Table of n, a(n) for n=0..67.

Mathematica

a[0] = 0; a[n_] := a[n] = Block[{k = 1, idm = IntegerDigits[ a[n - 1], 8], t = a@# & /@ Range[n - 1]}, Label[ start]; While[ MemberQ[t, k], k++];  While[ Select[ Permutations[ Join[ idm, IntegerDigits[k, 8]]], #[[1]] != 0 && # == Reverse@# &] == {}, k++; Goto[ start]]; k]; s = Array[a, 60, 0]

Crossrefs

Cf. A230892, A231921, A231923, A231925, A231927, A231929, A231933, A228407, A231930.

Sequence in context: A075700 A021843 A362752 * A175615 A200696 A203130

Adjacent sequences: A231928 A231929 A231930 * A231932 A231933 A231934

Keyword

nonn,base,easy

Author

N. J. A. Sloane and Robert G. Wilson v, Nov 15 2013

Status

approved