A231929 Terms of A231928 written in base 10: the binary expansions of a(n) and a(n+1) taken together can be rearranged to form a palindrome.

0, 8, 1, 7, 49, 9, 2, 14, 50, 16, 3, 10, 22, 52, 21, 56, 24, 4, 11, 29, 53, 28, 60, 18, 30, 58, 15, 51, 63, 99, 105, 343, 54, 12, 5, 19, 37, 61, 26, 38, 59, 17, 23, 64, 20, 6, 13, 43, 55, 42, 62, 27, 45, 71, 25, 31, 74, 80, 158, 176, 206, 218, 346, 57, 32, 40, 48, 65, 36

Offset

0,2

Comments

See A231928 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..68.

Mathematica

a[0] = 0; a[n_] := a[n] = Block[{k = 1, idm = IntegerDigits[ a[n - 1], 7], t = a@# & /@ Range[n - 1]}, Label[ start]; While[ MemberQ[t, k], k++];  While[ Select[ Permutations[ Join[ idm, IntegerDigits[k, 7]]], #[[1]] != 0 && # == Reverse@# &] == {}, k++; Goto[ start]]; k]; s = Array[a, 60, 0]

Crossrefs

Cf. A230892, A231921, A231923, A231925, A231927, A231931, A231933, A228407, A231928.

Sequence in context: A234614 A199872 A143548 * A154460 A021554 A021059

Adjacent sequences: A231926 A231927 A231928 * A231930 A231931 A231932

Keyword

nonn,base,easy

Author

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

Status

approved