A020991
Largest value of k for which Golay-Rudin-Shapiro sequence A020986(k) = n.
Original entry on oeis.org
0, 3, 6, 15, 26, 27, 30, 63, 106, 107, 110, 111, 122, 123, 126, 255, 426, 427, 430, 431, 442, 443, 446, 447, 490, 491, 494, 495, 506, 507, 510, 1023, 1706, 1707, 1710, 1711, 1722, 1723, 1726, 1727, 1770, 1771, 1774, 1775, 1786, 1787, 1790, 1791, 1962, 1963
Offset: 1
A093573
Triangle read by rows: row n gives positions where n occurs in the Golay-Rudin-Shapiro related sequence A020986.
Original entry on oeis.org
0, 1, 3, 2, 4, 6, 5, 7, 13, 15, 8, 12, 14, 16, 26, 9, 11, 17, 19, 25, 27, 10, 18, 20, 22, 24, 28, 30, 21, 23, 29, 31, 53, 55, 61, 63, 32, 50, 52, 54, 56, 60, 62, 64, 106, 33, 35, 49, 51, 57, 59, 65, 67, 105, 107, 34, 36, 38, 48, 58, 66, 68, 70, 104, 108, 110, 37, 39, 45, 47, 69, 71, 77, 79, 101, 103, 109, 111
Offset: 1
A020986(n) for n = 0, 1, ... is 1, 2, 3, 2, 3, 4, 3, 4, 5, 6, ..., so the positions of 1, 2, 3, 4, ... are 0; 1, 3; 2, 4, 6; 5, 7, 13, 15; ...
From _Seiichi Manyama_, Apr 23 2017: (Start)
Triangle begins:
0,
1, 3,
2, 4, 6,
5, 7, 13, 15,
8, 12, 14, 16, 26,
9, 11, 17, 19, 25, 27,
10, 18, 20, 22, 24, 28, 30,
21, 23, 29, 31, 53, 55, 61, 63,
32, 50, 52, 54, 56, 60, 62, 64, 106,
33, 35, 49, 51, 57, 59, 65, 67, 105, 107,
34, 36, 38, 48, 58, 66, 68, 70, 104, 108, 110,
... (End)
-
a093573 n k = a093573_row n !! (k-1)
a093573_row n = take n $ elemIndices n a020986_list
a093573_tabl = map a093573_row [1..]
-- Reinhard Zumkeller, Jun 06 2012
-
With[{n = 16}, TakeWhile[#, Length@ #2 == #1 & @@ # &][[All, -1]] &@ Transpose@ {Keys@ #, Lookup[#, Keys@ #]} &[PositionIndex@ Accumulate@ Array[1 - 2 Mod[Length[FixedPointList[BitAnd[#, # - 1] &, BitAnd[#, Quotient[#, 2]]]], 2] &, n^2, 0] - 1]] // Flatten (* Michael De Vlieger, Jan 25 2020 *)
Showing 1-2 of 2 results.
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