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A140253
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a(2*n) = 2*(2*4^(n-1)-1) and a(2*n-1) = 2*4^(n-1)-1.
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1
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-1, 1, 2, 7, 14, 31, 62, 127, 254, 511, 1022, 2047, 4094, 8191, 16382, 32767, 65534, 131071, 262142, 524287, 1048574, 2097151, 4194302, 8388607, 16777214, 33554431, 67108862, 134217727, 268435454, 536870911
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| The inverse binomial transform is 1, 1, 4, -2, 10, -14, 34, -62 which leads to (-1)^(n+1)*A135440(n).
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FORMULA
| a(2*n) = 2*A083420(n-1) and a(2*n+1) = A083420(n)
a(n+1) - a(n) = A014551(n); Jacobsthal-Lucas numbers.
a(2*n) + a(2*n+1) = 9*A002450(n)
a(n+1) - 2*a(n) = A010674(n+1); repeat 3, 0.
a(n) + A000034(n+1) = A000079(n); powers of 2.
a(n)= a(n-1) + 2*a(n-2) + 3 [From Gary Detlefs (gdetlefs(AT)aol.com), Jun 22 2010]
a(n+1) = A000069(2^n); odious numbers [Johannes W. Meijer, Jun 24 2011]
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MAPLE
| A140253:=proc(n): if type(n, odd) then 2*4^(((n+1)/2)-1)-1 else 2*(2*4^((n/2)-1)-1) fi: end: seq(A140253(n), n=0..29); [Johannes W. Meijer, Jun 24 2011]
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CROSSREFS
| Sequence in context: A018437 A120739 A034791 * A018453 A000147 A128902
Adjacent sequences: A140250 A140251 A140252 * A140254 A140255 A140256
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KEYWORD
| sign,easy
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AUTHOR
| Paul Curtz (bpcrtz(AT)free.fr), Jun 23 2008
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EXTENSIONS
| Edited, corrected and information added by Johannes W. Meijer Jun 24 2011
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