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A147540
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Numbers whose binary representation is the concatenation of 2n-1 digits 1, n digits 0 and 2n-1 digits 1.
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4
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5, 231, 7967, 260223, 8372735, 268306431, 8588894207, 274869551103, 8796026044415, 281474440364031, 9007194961870847, 288230341800361983, 9223371762010423295, 295147902980463788031, 9444732948147641253887
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| a(n) is the number whose binary representation is A138826(n).
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FORMULA
| a(n) = 2^(2n-1)-1+2^(5n-2)-2^(3n-1). Gf: x(5+6x-128x^2+768x^3) / ((1-4x)(1-x)(1-32x)(1-8x)). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 09 2008]
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MATHEMATICA
| Table[FromDigits[Join[Table[1, {2n - 1}], Table[0, {n}], Table[1, {2n - 1}]], 2], {n, 1, 15}] [From Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Nov 11 2008]
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CROSSREFS
| Cf. A138826.
Sequence in context: A103732 A065757 A157776 * A187366 A176898 A142668
Adjacent sequences: A147537 A147538 A147539 * A147541 A147542 A147543
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KEYWORD
| base,easy,nonn
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AUTHOR
| Omar E. Pol (info(AT)polprimos.com), Nov 06 2008
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EXTENSIONS
| More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl) and Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Nov 11 2008
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