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A158561 a(n) = ((2^n)*((2^n)+1) - (2^(n-1))*((2^(n-1))+1))/2, a(1)=3. 1
3, 7, 26, 100, 392, 1552, 6176, 24640, 98432, 393472, 1573376, 6292480, 25167872, 100667392, 402661376, 1610629120, 6442483712, 25769869312, 103079346176, 412317122560, 1649267965952, 6597070815232, 26388281163776, 105553120460800, 422212473454592 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
a(n) gives the number of elements with the length of n-digits, base B, in the addition matrix <0;B^n -1> x <0;B^n -1>. a(1)=B*(B+1)/2. a(n)=((B^n)*((B^n)+1) - (B^(n-1))*((B^(n-1))+1))/2.
Essentially the same as A049775. [R. J. Mathar, Mar 26 2009]
LINKS
FORMULA
G.f.: x*(1-x)*(3-8*x)/((1-2*x)*(1-4*x)). [Jaume Oliver Lafont, Mar 27 2009]
G.f.: (3-11*x+8*x^2)/(1-6*x+8*x^2). - Harvey P. Dale, Feb 25 2017
MATHEMATICA
LinearRecurrence[{6, -8}, {3, 7, 26}, 30] (* Harvey P. Dale, Feb 25 2017 *)
CROSSREFS
Cf. A006516. [Jaume Oliver Lafont, Mar 27 2009]
Sequence in context: A215018 A069738 A057005 * A252786 A108217 A120120
KEYWORD
easy,nonn
AUTHOR
Ctibor O. Zizka, Mar 21 2009
EXTENSIONS
More terms from Harvey P. Dale, Feb 25 2017
STATUS
approved

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Last modified July 12 19:59 EDT 2024. Contains 374252 sequences. (Running on oeis4.)