OFFSET
0,3
COMMENTS
a(n)/10^n converges to 110/729=0.15089163237311...
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (13,-33,31,-10).
FORMULA
a(n) =(10^n-1)*(110/729)-n^2/9-n*(20/81).
G.f.: (x^2+x)/((x-1)^3*(10*x-1)). - Harvey P. Dale, Mar 20 2011
MATHEMATICA
CoefficientList[Series[(x^2+x)/((x-1)^3 (10x-1)), {x, 0, 30}], x] (* Harvey P. Dale, Mar 20 2011 *)
RecurrenceTable[{a[0] == 0, a[n] == 10*a[n-1] + n^2}, a, {n, 100}] (* Vincenzo Librandi, Mar 10 2013 *)
LinearRecurrence[{13, -33, 31, -10}, {0, 1, 14, 149}, 20] (* Harvey P. Dale, May 25 2024 *)
PROG
(Magma) [0] cat [n le 1 select n else 10*Self(n-1)+n^2: n in [1..20]]; // Vincenzo Librandi, Mar 10 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Henry Bottomley, Jul 04 2000
STATUS
approved