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A281377
Write n in Elias's omega code, interchange the 1's and 0's and convert it back to decimal.
1
1, 3, 1, 23, 21, 19, 17, 15, 13, 11, 9, 7, 5, 3, 1, 735, 733, 731, 729, 727, 725, 723, 721, 719, 717, 715, 713, 711, 709, 707, 705, 1343, 1341, 1339, 1337, 1335, 1333, 1331, 1329, 1327, 1325, 1323, 1321, 1319, 1317, 1315, 1313, 1311, 1309, 1307, 1305, 1303, 1301, 1299, 1297, 1295, 1293
OFFSET
1,2
LINKS
EXAMPLE
For n = 10, the Elias omega code for n is '1110100', which after interchanging the 1's and 0's becomes '0001011'. Now, 1011_2 = 11_10. So, a(10) = 11.
PROG
(Python)
def a(n):
....s=""
....for i in A281193(n):
........if i=="1":
............s+="0"
........else:
............s+="1"
....return int(s, 2)
CROSSREFS
Cf. A035327, A054429 (n is converted to Elias gamma code, the 1's and 0's are interchanged and the code is converted back to decimal, for n>1), A281193, A281313.
Sequence in context: A270277 A271605 A270220 * A138654 A175289 A072271
KEYWORD
nonn,base
AUTHOR
Indranil Ghosh, Jan 21 2017
STATUS
approved