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.

Showing 1-2 of 2 results.

A167013 Number of Level 3 hexagonal polyominoes with cheesy blocks and n cells.

Original entry on oeis.org

1, 3, 11, 44, 186, 812, 3614, 16259, 73558, 333683, 1515454, 6885303, 31283654, 142121322, 645545957, 2931714681, 13312277095, 60440946141, 274391188445, 1245601594285, 5654137180147, 25664803641528, 116492672036579, 528751598530367
Offset: 1

Views

Author

Jonathan Vos Post, Oct 26 2009

Keywords

Comments

From Table 1, p.24, of Feretic. By level 0 cheesy polyominoes, and so too by level 0 polyominoes with cheesy blocks, Feretic appears to mean the usual column-convex polyominoes (A059716). See the paper for his definition.

Crossrefs

Formula

G.f.: (x*(1 - 24*x + 264*x^2 - 1766*x^3 + 8033*x^4 - 26297*x^5 + 63860*x^6 - 116445*x^7 + 157849*x^8 - 148533*x^9 + 61825*x^10 + 99443*x^11 - 308464*x^12 + 519182*x^13 - 655900*x^14 + 618461*x^15 - 344081*x^16 - 101610*x^17 + 519331*x^18 - 707969*x^19 + 601249*x^20 - 284943*x^21 - 68043*x^22 + 297023*x^23 - 346370*x^24 + 265550*x^25 - 140577*x^26 + 31503*x^27 + 64681*x^28 - 166424*x^29 + 234520*x^30 - 218182*x^31 + 130432*x^32 - 29144*x^33 - 33391*x^34 + 38482*x^35 - 12237*x^36 - 2050*x^37 - 6144*x^38 + 18593*x^39 - 21514*x^40 + 11634*x^41 + 3351*x^42 - 13907*x^43 + 12096*x^44 + 2302*x^45 - 8825*x^46 + 570*x^47 + 4681*x^48 - 1695*x^49 - 1519*x^50 + 1290*x^51 + 64*x^52 - 224*x^53 + 44*x^54 - 12*x^55)) / (1 - 27*x + 334*x^2 - 2515*x^3 + 12906*x^4 - 47836*x^5 + 132248*x^6 - 276956*x^7 + 438796*x^8 - 508406*x^9 + 365771*x^10 + 36865*x^11 - 648120*x^12 + 1344653*x^13 - 1932847*x^14 + 2126787*x^15 - 1632701*x^16 + 408884*x^17 + 1117382*x^18 - 2223607*x^19 + 2392085*x^20 - 1636807*x^21 + 418146*x^22 + 665251*x^23 - 1211688*x^24 + 1191386*x^25 - 838060*x^26 + 416174*x^27 - 41907*x^28 - 323733*x^29 + 664097*x^30 - 810808*x^31 + 657803*x^32 - 319442*x^33 + 14159*x^34 + 120746*x^35 - 95202*x^36 + 22341*x^37 - 7930*x^38 + 47294*x^39 - 74720*x^40 + 62640*x^41 - 19120*x^42 - 28394*x^43 + 46822*x^44 - 21864*x^45 - 18416*x^46 + 20930*x^47 + 6617*x^48 - 14093*x^49 + 982*x^50 + 5867*x^51 - 2682*x^52 - 642*x^53 + 608*x^54 - 88*x^55 + 12*x^56).

Extensions

Edited by Ralf Stephan, Feb 07 2014
Extended by Ray Chandler, Jul 16 2015

A167011 Number of Level 1 hexagonal polyominoes with cheesy blocks and n cells.

Original entry on oeis.org

1, 3, 11, 44, 184, 784, 3363, 14451, 62097, 266716, 1145074, 4914448, 21087401, 90472315, 388129627, 1665025084, 7142592112, 30639836360, 131436162099, 563822359859, 2418629133001, 10375190596724, 44506436288882, 190919170388912, 818985577308225, 3513200788519075
Offset: 1

Views

Author

Jonathan Vos Post, Oct 26 2009

Keywords

Comments

From Table 1, p.24, of Feretic. By level 0 cheesy polyominoes, and so too by level 0 polyominoes with cheesy blocks, Feretic appears to mean the usual column-convex polyominoes (A059716). See the paper for his definition.

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{9,-27,32,-13,3,1},{1,3,11,44,184,784},26] (* Ray Chandler, Jul 16 2015 *)
    Rest[CoefficientList[Series[x*(-1+6x-11x^2+6x^3-2x^4)/(-1+9x-27x^2+32x^3-13x^4+3x^5+x^6),{x,0,26}],x]] (* Ray Chandler, Jul 16 2015 *)

Formula

G.f.: x(-1+6x-11x^2+6x^3-2x^4)/(-1+9x-27x^2+32x^3-13x^4+3x^5+x^6).

Extensions

Edited by Ralf Stephan, Feb 07 2014
Showing 1-2 of 2 results.