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

1,2

Links

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

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

Adjacent sequences: A281374 A281375 A281376 * A281378 A281379 A281380

Keyword

nonn,base

Author

Indranil Ghosh, Jan 21 2017

Status

approved