

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.


7



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
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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



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



KEYWORD

nonn,base,easy


AUTHOR



STATUS

approved



