A281223 The decimal representation of the Elias omega code for n (A281193(n)).

0, 4, 6, 40, 42, 44, 46, 112, 114, 116, 118, 120, 122, 124, 126, 1312, 1314, 1316, 1318, 1320, 1322, 1324, 1326, 1328, 1330, 1332, 1334, 1336, 1338, 1340, 1342, 2752, 2754, 2756, 2758, 2760, 2762, 2764, 2766, 2768, 2770, 2772, 2774, 2776, 2778, 2780, 2782, 2784, 2786, 2788, 2790

Offset: 1

Author

Indranil Ghosh, Jan 18 2017

Keywords

• nonn
• base

Examples

			For n = 6, the Elias omega code for 6 is '101100' which is 44 in decimal. So, a(6) = 44.
		

Links

• Indranil Ghosh, Table of n, a(n) for n = 1..10000
• Khalid Sayood (Editor), Lossless Compression Handbook, Chapter 3 - Universal Codes, p. 59, section 3.6.
• Wikipedia, Elias omega coding

Crossrefs

Cf. A281193, A171885 (Decimal representation of the Elias gamma code for n).

Programs

Python

def E(n):
    s=""
    if n==1:
        return "0"
    else:
        b=(bin(n)[2:])
        s+=E(len(b)-1)+b
    return s
def elias_omega(n):
    return int(E(n)[1:]+"0",2)