A281377 Write n in Elias's omega code, interchange the 1's and 0's and convert it back to decimal.

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

Author

Indranil Ghosh, Jan 21 2017

Keywords

• nonn
• base

Examples

			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.
		

Links

• Indranil Ghosh, Table of n, a(n) for n = 1..10000

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.

Programs

Python

def a(n):
    s=""
    for i in A281193(n):
        if i=="1":
            s+="0"
        else:
            s+="1"
    return int(s, 2)