OFFSET
0,2
COMMENTS
Partial sums of A109241.
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..100
Index entries for linear recurrences with constant coefficients, signature (111,-1110,1000).
FORMULA
a(n) = 10^(2*n+3)/891 - 10^(n+1)/81 + 1/891.
a(n) = 111*a(n-1) - 1110*a(n-2) + 1000*a(n-3).
a(n) = 110*a(n-1) - 1000*a(n-2) + 1, n >= 2. - Vincenzo Librandi, Mar 18 2011
EXAMPLE
The numbers of 1's, 2's, 3's etc. appearing occur according to
1:1,3,4,4,4,4,4,4,...
2:0,0,1,3,4,4,4,4,...
3:0,0,0,0,1,3,4,4,...
4:0,0,0,0,0,0,1,3,... etc. up to term 17, where 9->10 etc. changes the pattern.
PROG
(Sage) [gaussian_binomial(n, 2, 10) for n in range(2, 14)] # Zerinvary Lajos, May 27 2009
(PARI) a(n) = {10^(2*n+3)/891 - 10^(n+1)/81 + 1/891} \\ Andrew Howroyd, Nov 08 2019
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Jun 23 2005
EXTENSIONS
Terms a(12) and beyond from Andrew Howroyd, Nov 08 2019
STATUS
approved