OFFSET
1,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..200
Index entries for linear recurrences with constant coefficients, signature (20, -37, 18).
FORMULA
a(1)=1, a(2)=20, a(3)=363, a(n) = 20*a(n-1) - 37*a(n-2) + 18*a(n-3). - Vincenzo Librandi, Oct 20 2012
MATHEMATICA
LinearRecurrence[{20, -37, 18}, {1, 20, 363}, 20] (* Vincenzo Librandi, Oct 20 2012 *)
nxt[{n_, a_}]:={n+1, 18a+n+1}; NestList[nxt, {1, 1}, 20][[All, 2]] (* Harvey P. Dale, Oct 08 2017 *)
PROG
(Magma) I:=[1, 20, 363]; [n le 3 select I[n] else 20*Self(n-1) - 37*Self(n-2) + 18*Self(n-3): n in [1..20]]; // Vincenzo Librandi, Oct 20 2012
(Maxima)
a[1]:1$
a[2]:20$
a[3]:363$
a[n]:=20*a[n-1]-37*a[n-2]+18*a[n-3]$
A014901(n):=a[n]$
makelist(A014901(n), n, 1, 30); /* Martin Ettl, Nov 06 2012 */
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved