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A083318 a(0) = 1; for n>0, a(n) = 2^n+1. +0
7
1, 3, 5, 9, 17, 33, 65, 129, 257, 513, 1025, 2049, 4097, 8193, 16385, 32769, 65537, 131073, 262145, 524289, 1048577, 2097153, 4194305, 8388609, 16777217, 33554433, 67108865, 134217729, 268435457, 536870913, 1073741825, 2147483649 (list; graph; listen)
OFFSET

0,2

COMMENT

Inverse binomial transform of A005056.

Also, A000533 interpreted as binary numbers, written in base 10. Numbers whose representation in base 2 is has n+1 digits and the digit "1" is the initial and final digit and if n>1 then the internal digits are "0" (See example). - Omar E. Pol (info(AT)polprimos.com), Feb 24 2008

FORMULA

a(n)=2^n+1^n-0^n. G.f. (1-2x^2)/((1-x)(1-2x)). E.g.f. exp(2x)+exp(x)-exp(0).

a(n)=sum{k=0..n, 0^(k(n-k))2^(n-k)} - Paul Barry (pbarry(AT)wit.ie), Feb 09 2005

a(n) = Min{m: A008687(m) = n+1}. - Reinhard Zumkeller (reinhard.zumkeller(AT)lhsystems.com), Jul 25 2006

Row sums of triangle A132749; = binomial transform of [1, 2, 0, 2, 0, 2, 0, 2,...]. - Gary W. Adamson (qntmpkt(AT)yahoo.com), Aug 28 2007

EXAMPLE

------------------------------

n .... a(n) .. a(n) in base 2

------------------------------

0 ..... 1 ..... 1

1 ..... 3 ..... 11

2 ..... 5 ..... 101

3 ..... 9 ..... 1001

4 .... 17 ..... 10001

5 .... 33 ..... 100001

6 .... 65 ..... 1000001

7 ... 129 ..... 10000001

8 ... 257 ..... 100000001

9 ... 513 ..... 1000000001

CROSSREFS

Except for the leading term, the same as A000051. Cf. A083319.

Cf. A132749.

Cf. A000533.

Adjacent sequences: A083315 A083316 A083317 this_sequence A083319 A083320 A083321

Sequence in context: A074858 A074860 A135728 this_sequence A127904 A048578 A087312

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Apr 25 2003

EXTENSIONS

Edited by njas, Sep 28 2007

Examples provided by Omar E. Pol (info(AT)polprimos.com), Feb 24 2008.

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Last modified May 16 01:24 EDT 2008. Contains 139630 sequences.


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