|
| |
|
|
A008592
|
|
Multiples of 10.
|
|
32
| |
|
|
0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| Number of 3 X n binary matrices avoiding simultaneously the right angled numbered polyomino patterns (ranpp) (00;1), (01,1) and (11;0). An occurrence of a ranpp (xy;z) in a matrix A=(a(i,j)) is a triple (a(i1,j1), a(i1,j2), a(i2,j1)) where i1<i2, j1<j2 and these elements are in the same relative order as those in the triple (x,y,z). In general, the number of m X n 0-1 matrices in question is given by (n+2)*2^(m-1)+2*m*(n-1)-2 for m>1 and n>1. - Sergey Kitaev (kitaev(AT)ms.uky.edu), Nov 12 2004
If Y is a 5-subset of an n-set X then, for n>=5, a(n-4) is the number of 3-subsets of X having at least two elements in common with Y. - Milan R. Janjic (agnus(AT)blic.net), Dec 08 2007
Complement of A067251; A168184(a(n)) = 0. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 30 2009]
Where record values occur for number of partitions of n into powers of 10: A179052(n)=A179051(a(n)). [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 27 2010]
|
|
|
LINKS
| Tanya Khovanova, Recursive Sequences
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 322
S. Kitaev, On multi-avoidance of right angled numbered polyomino patterns, Integers: Electronic Journal of Combinatorial Number Theory 4 (2004), A21, 20pp.
|
|
|
FORMULA
| a(n) = 10*n = 2*a(n-1)-a(n-2). G.f.: 10x/(x-1)^2. [From Vincenzo Librandi, Dec 24 2010]
|
|
|
MATHEMATICA
| Range[0, 1000, 10] (* From Vladimir Joseph Stephan Orlovsky (4vladimir(AT)gmail.com), May 28 2011 *)
|
|
|
CROSSREFS
| Cf. A008590, A008591.
Sequence in context: A096092 A109597 A194233 * A158814 A118959 A043489
Adjacent sequences: A008589 A008590 A008591 * A008593 A008594 A008595
|
|
|
KEYWORD
| nonn,easy
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
|
| |
|
|
