cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A220133 Number of tilings of an n X 8 rectangle using integer-sided rectangular tiles of area n.

Original entry on oeis.org

1, 1, 34, 13, 143, 5, 209, 3, 250, 13, 44, 1, 472, 1, 36, 19, 250, 1, 209, 1, 153, 15, 34, 1, 681, 5, 34, 13, 145, 1, 221, 1, 250, 13, 34, 7, 472, 1, 34, 13, 260, 1, 211, 1, 143, 19, 34, 1, 681, 3, 44, 13, 143, 1, 209, 5, 252, 13, 34, 1, 484, 1, 34, 15, 250, 5
Offset: 0

Views

Author

Alois P. Heinz, Dec 06 2012

Keywords

Comments

1 followed by period 840: (1, 34, ..., 695) repeated; offset 0.

Examples

			a(5) = 5, because there are 5 tilings of a 5 X 8 rectangle using integer-sided rectangular tiles of area 5:
._._._._._._._._.   ._________._._._.   ._._________._._.
| | | | | | | | |   |_________| | | |   | |_________| | |
| | | | | | | | |   |_________| | | |   | |_________| | |
| | | | | | | | |   |_________| | | |   | |_________| | |
| | | | | | | | |   |_________| | | |   | |_________| | |
|_|_|_|_|_|_|_|_|   |_________|_|_|_|   |_|_________|_|_|
._._._________._.   ._._._._________.
| | |_________| |   | | | |_________|
| | |_________| |   | | | |_________|
| | |_________| |   | | | |_________|
| | |_________| |   | | | |_________|
|_|_|_________|_|   |_|_|_|_________|
		

Crossrefs

Row n=8 of A220122.

Programs

  • Maple
    gf:= -(694*x^46 +x^45 +728*x^44 +708*x^43 +872*x^42 +1441*x^41 +1789*x^40 +928*x^39 +2784*x^38 +1967*x^37 +2307*x^36 +3029*x^35 +3122*x^34 +2593*x^33 +4196*x^32 +2514*x^31 +3854*x^30 +3978*x^29 +3762*x^28
    +3055*x^27 +4448*x^26 +2969*x^25 +4154*x^24 +3352*x^23 +3461*x^22 +2969*x^21 +3755*x^20 +2362*x^19 +3069*x^18 +2592*x^17 +2468*x^16 +1821*x^15 +2117*x^14 +1207*x^13 +1736*x^12 +950*x^11 +921*x^10 +581*x^9 +705*x^8 +235*x^7 +403*x^6 +55*x^5 +179*x^4 +15*x^3 +35*x^2 +x +1) /
    (x^46 +x^44 +x^43 +x^42 +2*x^41 +2*x^40 +x^39 +3*x^38 +2*x^37 +2*x^36 +3*x^35 +2*x^34 +2*x^33 +3*x^32 +x^31 +2*x^30 +2*x^29 +x^28 +x^27 +x^26
    +x^24 -x^22 -x^20 -x^19 -x^18 -2*x^17 -2*x^16 -x^15 -3*x^14 -2*x^13 -2*x^12 -3*x^11 -2*x^10 -2*x^9 -3*x^8 -x^7 -2*x^6 -2*x^5 -x^4 -x^3 -x^2 -1):
    a:= n-> coeff(series(gf, x, n+1), x, n):
    seq(a(n), n=0..80);

Formula

G.f.: see Maple program.