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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.
7
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.
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]
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved