OFFSET
0,2
COMMENTS
From a quiz.
REFERENCES
K. Russell and P. Carter, Number Puzzles, W. Foulsham and Co. Ltd. (1993).
LINKS
Index entries for linear recurrences with constant coefficients, signature (9, -15, 7).
FORMULA
G.f.: -(((x-3)*x+1)/((x-1)^2*(7*x-1))). - Harvey P. Dale, Jun 15 2011
a(0)=1, a(1)=6, a(2)=40, a(n)=9*a(n-1)-15*a(n-2)+7*a(n-3). - Harvey P. Dale, Jun 15 2011
MATHEMATICA
RecurrenceTable[{a[0]==1, a[n]==7a[n-1]-n}, a[n], {n, 0, 20}] (* or *) LinearRecurrence[{9, -15, 7}, {1, 6, 40}, 31](* Harvey P. Dale, Jun 15 2011 *)
PROG
(PARI) a(n)=if(n>0, 7*a(n-1)-n, 1) for(n=0, 30, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Herman Jamke (hermanjamke(AT)fastmail.fm), Sep 14 2006
STATUS
approved