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