The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 60th year, we have over 367,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A099945 Number of 4 X n binary matrices avoiding simultaneously the right angled numbered polyomino patterns (ranpp) (00;1) and (11;0). 0
 188, 404, 836, 1700, 3428, 6884, 13796, 27620, 55268, 110564, 221156, 442340, 884708, 1769444, 3538916, 7077860, 14155748, 28311524, 56623076, 113246180, 226492388, 452984804, 905969636, 1811939300, 3623878628, 7247757284 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,1 COMMENTS 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 i10 and n>2; for n=2 the number is (m+1)*2^m. LINKS Table of n, a(n) for n=3..28. S. Kitaev, On multi-avoidance of right angled numbered polyomino patterns, Integers: Electronic Journal of Combinatorial Number Theory 4 (2004), A21, 20pp. Index entries for linear recurrences with constant coefficients, signature (3, -2). FORMULA a(n) = 27*2^n-28. PROG (PARI) vector(50, n, i=n+2; 27*2^i-28) \\ Michel Marcus, Dec 01 2014 CROSSREFS Cf. A000105. Sequence in context: A186397 A260836 A304279 * A211814 A335592 A233786 Adjacent sequences: A099942 A099943 A099944 * A099946 A099947 A099948 KEYWORD nonn AUTHOR Sergey Kitaev, Nov 12 2004 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 4 15:16 EST 2023. Contains 367563 sequences. (Running on oeis4.)