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A287374
Positions of 1 in A101666.
4
2, 3, 5, 7, 9, 11, 13, 16, 17, 19, 21, 24, 25, 27, 30, 31, 33, 35, 37, 40, 41, 43, 46, 47, 49, 51, 53, 56, 58, 59, 61, 63, 65, 67, 69, 72, 73, 75, 78, 79, 81, 83, 85, 88, 90, 91, 93, 95, 97, 99, 101, 104, 105, 107, 110, 111, 114, 115, 117, 119, 121, 123, 125
OFFSET
1,1
COMMENTS
2n - a(n) is in {0,1} for n >= 1. The first 20 numbers 2n - a(n) are 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, with 0 is positions given by A287373.
LINKS
FORMULA
a(n) = (1/2)*A287375(n) for n >= 1.
MATHEMATICA
s = Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {1, 2}, 2 -> {1, 0}}] &, {0}, 12] (* A101666 *)
Flatten[Position[s, 0]] (* A287373 *)
Flatten[Position[s, 1]] (* A287374 *)
Flatten[Position[s, 2]] (* A287375 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, May 25 2017
STATUS
approved