0,1

Same as Pisot sequences E(2,8), L(2,8), P(2,8), T(2,8). See A008776 for definitions of Pisot sequences.

In the Chebyshev polynomial of degree 2n, a(n) is the coefficient of x^2n. - Benoit Cloitre (benoit7848c(AT)orange.fr), Mar 13 2002

1/2 - 1/8 + 1/32 - 1/128 + ... = 2/5 [From Gary W. Adamson (qntmpkt(AT)yahoo.com), Mar 03 2009]

Numbers n such that n^3+(n/2)^3=9*n^3/8 is square [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 05 2009]

Index entries for sequences related to linear recurrences with constant coefficients

Milan Janjic, Enumerative Formulas for Some Functions on Finite Sets

Tanya Khovanova, Recursive Sequences

a(n) = 2*4^n; a(n) = 4a(n-1).

1 = 1/2 + Sum(n = 1 through infinity) 3/a(n) = 3/6 + 3/8 + 3/32 + 3/128 + 3/512 + 3/2048...; with partial sums: 1/2, 31/32, 127/128, 511/512, 2047/2048... - Gary W. Adamson (qntmpkt(AT)yahoo.com), Jun 16 2003

a(n)=2*A000302(n) . G.f.: 2/(1-4*x). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 23 2008]

a(n) = A081294(n+1) = A028403(n+1) - A000079(n+1) for n >=1. a(n-1) = A028403(n) - A000079(n). [From Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), Jul 27 2009]

For n=2, 9*8/8=3^2; n=8, 9*8^3/8=24^2; n=32, 9*32^3/8=192^2 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Aug 05 2009]

seq(count(Subset(n))*count(Composition(n)), n=1..25); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Oct 16 2006

with(finance):seq(futurevalue(2, 3, n), n=0..24); # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Mar 25 2009]

(Other) sage: [lucas_number1(2*n, 2, 0) for n in xrange(1, 26)] # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Oct 27 2009]

Absolute value of A009117. Essentially the same as A081294.

A164632. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Aug 23 2009]

Adjacent sequences: A004168 A004169 A004170 this_sequence A004172 A004173 A004174

Sequence in context: A145682 A099752 A081294 this_sequence A009117 A160637 A150829

easy,nonn,new

N. J. A. Sloane (njas(AT)research.att.com).