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A288605
Position of first appearance of each integer in A088568 (number of 1's minus number of 2's in first n terms of A000002).
13
0, 1, 3, 12, 32, 93, 257, 378, 471, 798, 825, 858, 1127, 1398, 1497, 1524, 1533, 6352, 6969, 7176, 7269, 7566, 7971, 20338, 20371, 21982, 22009, 25638, 25665, 25692, 27969, 39184, 39211, 42398, 43129, 43150, 48637, 48730, 48757, 49014, 49041, 49068, 49095, 49864
OFFSET
1,3
COMMENTS
For the definition of this sequence we assume A088568(0) = 0.
EXAMPLE
A088568(12) = -2 is the first appearance of -2 in A088568, so 12 belongs to the sequence.
A088568(32) = 2 is the first appearance of 2, so 32 belongs to the sequence.
MATHEMATICA
Map[First, Values@ #] - 1 &@ PositionIndex@ Prepend[#, 0] &@ MapIndexed[3 First@ #2 - 2 #1 &, Accumulate@ Prepend[Nest[Flatten[Partition[#, 2] /. {{2, 2} -> {2, 2, 1, 1}, {2, 1} -> {2, 2, 1}, {1, 2} -> {2, 1, 1}, {1, 1} -> {2, 1}}] &, {2, 2}, 25], 1]] (* Michael De Vlieger, Jun 12 2017, after Birkas Gyorgy at A000002 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jun 11 2017
STATUS
approved