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A144129 ChebyshevT[3,n]. 3
0, 1, 26, 99, 244, 485, 846, 1351, 2024, 2889, 3970, 5291, 6876, 8749, 10934, 13455, 16336, 19601, 23274, 27379, 31940, 36981, 42526, 48599, 55224, 62425, 70226, 78651, 87724, 97469, 107910, 119071, 130976, 143649, 157114, 171395, 186516 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

a(n) = 4*n^3 - 3*n. [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Jan 11 2009]

Contribution from Peter Luschny (peter(AT)luschny.de), Jul 12 2009: (Start)

The general formula for alternating sums of powers of odd integers is in terms of the Swiss-Knife polynomials P(n,x) A153641 (P(n,0)-(-1)^k*P(n,2*k))/2. Here n=3, thus

a(k) = |(P(3,0)-(-1)^k*P(3,2*k))/2|. (End)

LINKS

Index to sequences with linear recurrences with constant coefficients, signature (4,-6,4,-1).

FORMULA

G.f.: x*(1+22*x+x^2)/(1-x)^4. [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Jan 11 2009]

a(n)=Cosh[3*ArcCosh[n]]=Cos[3*ArcCos[n]] [From Artur Jasinski (grafix(AT)csl.pl), Feb 14 2010]

MAPLE

a := n -> (4*n^2-3)*n; [From Peter Luschny (peter(AT)luschny.de), Jul 12 2009]

MATHEMATICA

lst={}; Do[AppendTo[lst, ChebyshevT[3, n]], {n, 0, 10^2}]; lst

Round[Table[N[Cosh[3 ArcCosh[n]], 100], {n, 0, 20}]] [From Artur Jasinski (grafix(AT)csl.pl), Feb 14 2010]

PROG

(MAGMA) [ 4*n^3-3*n: n in [0..36] ]; [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Jan 11 2009]

(PARI) a(n) = 4*n^3-3*n \\ Charles R Greathouse IV, Feb 08 2012

CROSSREFS

Sequence in context: A095796 A175549 A159541 * A026915 A136293 A065013

Adjacent sequences:  A144126 A144127 A144128 * A144130 A144131 A144132

KEYWORD

nonn,easy,changed

AUTHOR

Vladimir Orlovsky (4vladimir(AT)gmail.com), Sep 11 2008

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Last modified February 17 16:49 EST 2012. Contains 206058 sequences.