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A014937 a(1)=1, a(n)=n*20^(n-1)+a(n-1). 12
1, 41, 1241, 33241, 833241, 20033241, 468033241, 10708033241, 241108033241, 5361108033241, 118001108033241, 2575601108033241, 55823601108033241, 1202703601108033241, 25778703601108033241, 550066703601108033241 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
a(1)=1, a(2)=41, a(3)=1241, a(n)=41*a(n-1)-440*a(n-2)+400*a(n-3) From Harvey P. Dale, Jun 04 2012
G.f.: -x / ( (x-1)*(-1+20*x)^2 ). - R. J. Mathar, Nov 07 2015
MATHEMATICA
RecurrenceTable[{a[1]==1, a[n]==n*20^(n-1)+a[n-1]}, a, {n, 20}] (* or *) LinearRecurrence[{41, -440, 400}, {1, 41, 1241}, 20] (* Harvey P. Dale, Jun 04 2012 *)
CROSSREFS
Sequence in context: A196744 A196902 A297349 * A275225 A275145 A118451
KEYWORD
nonn,easy
AUTHOR
STATUS
approved

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Last modified April 21 11:49 EDT 2024. Contains 371870 sequences. (Running on oeis4.)