|
Search: id:A077416
|
|
|
| A077416 |
|
Chebyshev S-sequence with Diophantine property. |
|
+0 10
|
|
| 1, 13, 155, 1847, 22009, 262261, 3125123, 37239215, 443745457, 5287706269, 63008729771, 750817050983, 8946795882025, 106610733533317, 1270382006517779, 15137973344680031, 180385298129642593
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
COMMENT
|
7*b(n)^2 - 5*a(n)^2 = 2 with companion sequence b(n)=A077417(n), n>=0.
a(n) = L(n,-12)*(-1)^n, where L is defined as in A108299; see also A077417 for L(n,+12). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 01 2005
|
|
LINKS
|
Index entries for sequences related to linear recurrences with constant coefficients
Tanya Khovanova, Recursive Sequences
Index entries for sequences related to Chebyshev polynomials.
|
|
FORMULA
|
a(n) = 12*a(n-1) - a(n-2), a(-1)=-1, a(0)=1.
a(n) = S(n, 12) + S(n-1, 12) = S(2*n, sqrt(14)) with S(n, x) := U(n, x/2) Chebyshev's polynomials of the second kind. See A049310. S(-1, x)=0, S(n, 12)=A004191(n).
G.f.: (1+x)/(1-12*x+x^2).
a(n) = (ap^(2*n+1) - am^(2*n+1))/(ap - am) with ap := (sqrt(7)+sqrt(5))/sqrt(2) and am := (sqrt(7)-sqrt(5))/sqrt(2).
a(n)= sum(((-1)^k)*binomial(2*n-k, k)*14^(n-k), k=0..n).
a(n) = sqrt((7*A077417(n)^2 - 2)/5).
|
|
PROGRAM
|
(Other) sage: [(lucas_number2(n, 12, 1)-lucas_number2(n-1, 12, 1))/10 for n in xrange(1, 18)]# [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Nov 10 2009]
|
|
CROSSREFS
|
Cf. A054320(n-1) with companion A072256(n), n>=1.
Sequence in context: A097168 A108366 A163415 this_sequence A102146 A097827 A142104
Adjacent sequences: A077413 A077414 A077415 this_sequence A077417 A077418 A077419
|
|
KEYWORD
|
nonn,easy,new
|
|
AUTHOR
|
Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Nov 29 2002
|
|
|
Search completed in 0.002 seconds
|