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A302330
a(0)=1, a(1)=97; for n>1, a(n) = 98*a(n-1) - a(n-2).
5
1, 97, 9505, 931393, 91267009, 8943235489, 876345810913, 85872946233985, 8414672385119617, 824552020795488481, 80797683365572751521, 7917348417805334160577, 775819347261557174985025, 76022378683214797814371873, 7449417291607788628633458529
OFFSET
0,2
FORMULA
G.f.: (1 - x)/(1 - 98*x + x^2).
a(n) = a(-1-n).
a(n) = cosh((2*n + 1)*arccosh(5))/5.
a(n) = ((5 + 2*sqrt(6))^(2*n + 1) + 1/(5 + 2*sqrt(6))^(2*n + 1))/10.
a(n) = (1/5)*T(2*n+1, 5), where T(n,x) denotes the n-th Chebyshev polynomial of the first kind. - Peter Bala, Jul 08 2022
MATHEMATICA
LinearRecurrence[{98, -1}, {1, 97}, 20]
PROG
(PARI) x='x+O('x^99); Vec((1-x)/(1-98*x+x^2)) \\ Altug Alkan, Apr 06 2018
CROSSREFS
Fifth row of the array A188646.
First bisection of A041275, A042151.
Similar sequences of the type cosh((2*n+1)*arccosh(k))/k are listed in A302329.
Sequence in context: A069419 A189341 A189777 * A057011 A218591 A218205
KEYWORD
nonn,easy
AUTHOR
Bruno Berselli, Apr 05 2018
STATUS
approved