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 1-6 of 6 results.

A208252 Number of n X n 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.

Original entry on oeis.org

1, 12, 2040, 2445264, 20662697664, 1230875651548608, 516901401841519506624, 1530268623239822606574667872, 31936997040921403605588139690977984, 4698799611233642481043318409392291549604736
Offset: 1

Views

Author

R. H. Hardin Feb 24 2012

Keywords

Comments

Diagonal of A208258

Examples

			Some solutions for n=4
..0..0..0..1....0..0..0..0....0..0..1..2....0..0..0..0....0..0..0..1
..1..1..0..1....1..0..1..0....0..2..2..0....0..1..0..2....2..1..0..2
..2..2..1..0....2..2..1..2....2..0..0..1....2..0..1..2....2..0..1..2
..1..1..0..1....0..0..2..0....2..1..2..1....0..2..1..0....1..0..1..2
		

A208253 Number of n X 3 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.

Original entry on oeis.org

5, 96, 2040, 43344, 920928, 19566912, 415737216, 8833148160, 187677464064, 3987573838848, 84723785029632, 1800122089230336, 38247105402593280, 812634365429366784, 17266002353004576768, 366849901919230820352
Offset: 1

Views

Author

R. H. Hardin, Feb 24 2012

Keywords

Comments

Column 3 of A208258.

Examples

			Some solutions for n=4:
..0..0..1....0..0..0....0..1..0....0..0..1....0..0..0....0..1..2....0..0..1
..2..0..0....0..1..2....0..1..1....2..0..2....1..2..1....1..2..0....1..1..2
..2..0..1....2..0..0....1..0..2....0..2..0....0..2..2....0..1..0....1..0..1
..2..2..2....1..0..1....1..2..0....2..0..2....0..0..2....2..0..1....2..1..2
		

Crossrefs

Cf. A208258.

Formula

Empirical: a(n) = 22*a(n-1) - 16*a(n-2) for n>3.
Conjectures from Colin Barker, Jun 29 2018: (Start)
G.f.: x*(1 - 2*x)*(5 - 4*x) / (1 - 22*x + 16*x^2).
a(n) = (1/32)*sqrt(3/35)*((11-sqrt(105))^n*(-13+sqrt(105)) + (11+sqrt(105))^n*(13+sqrt(105))) for n>1.
(End)

A208254 Number of n X 4 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.

Original entry on oeis.org

14, 768, 43344, 2445264, 137947632, 7782199824, 439026252912, 24767296501776, 1397226183866736, 78823339024454928, 4446752320207192176, 250859789016717819408, 14152043831975777230704, 798375640062491402594064
Offset: 1

Views

Author

R. H. Hardin, Feb 24 2012

Keywords

Comments

Column 4 of A208258.

Examples

			Some solutions for n=4
..0..0..0..0....0..0..0..1....0..0..1..2....0..1..0..2....0..0..0..0
..1..0..1..0....2..0..1..0....0..2..2..0....1..2..2..1....1..2..2..2
..2..1..0..1....0..2..1..1....2..0..0..1....1..0..1..2....1..2..1..1
..2..0..1..0....2..0..0..1....2..1..2..1....0..1..2..0....1..2..1..2
		

Crossrefs

Cf. A208258.

Formula

Empirical: a(n) = 61*a(n-1) - 266*a(n-2) + 416*a(n-3) - 256*a(n-4) for n>5.
Empirical g.f.: 2*x*(7 - 43*x + 110*x^2 - 128*x^3 + 64*x^4) / (1 - 61*x + 266*x^2 - 416*x^3 + 256*x^4). - Colin Barker, Jun 29 2018

A208255 Number of nX5 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.

Original entry on oeis.org

41, 6144, 920928, 137947632, 20662697664, 3094987890864, 463586569433280, 69438884409258336, 10400988693344761104, 1557924881981189122032, 233355694295516814615312, 34953469637696859885114528
Offset: 1

Views

Author

R. H. Hardin Feb 24 2012

Keywords

Comments

Column 5 of A208258

Examples

			Some solutions for n=4
..0..0..1..2..0....0..0..0..0..1....0..1..0..2..2....0..0..1..2..2
..2..1..0..2..1....0..1..0..2..1....2..0..1..2..0....1..1..2..1..2
..2..1..2..0..1....0..0..2..0..0....1..1..2..1..0....1..2..0..2..0
..2..0..2..2..2....0..2..0..1..1....1..2..0..2..2....1..0..2..0..1
		

Formula

Empirical: a(n) = 171*a(n-1) -3370*a(n-2) +29805*a(n-3) -149108*a(n-4) +447784*a(n-5) -778496*a(n-6) +649216*a(n-7) -114688*a(n-8) for n>9

A208256 Number of nX6 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.

Original entry on oeis.org

122, 49152, 19566912, 7782199824, 3094987890864, 1230875651548608, 489518751475118880, 194681408759751734640, 77424717204435400421520, 30791778589670316720418080, 12245877840416847143166208896
Offset: 1

Views

Author

R. H. Hardin Feb 24 2012

Keywords

Comments

Column 6 of A208258

Examples

			Some solutions for n=4
..0..1..0..2..1..2....0..1..1..2..0..2....0..0..1..2..0..2....0..0..0..0..1..0
..2..1..1..0..1..1....2..0..1..1..0..1....1..0..2..1..2..1....0..1..2..1..0..1
..0..0..2..0..0..2....1..1..2..1..0..0....2..2..1..2..0..2....2..0..0..0..2..0
..0..1..0..1..2..0....0..1..2..1..0..2....2..0..0..0..2..1....0..1..1..1..0..1
		

Formula

Empirical: a(n) = 483*a(n-1) -37260*a(n-2) +1406078*a(n-3) -32825379*a(n-4) +522499249*a(n-5) -5935275892*a(n-6) +48955308778*a(n-7) -292045494268*a(n-8) +1227794612112*a(n-9) -3438890819616*a(n-10) +5747863337984*a(n-11) -4538037229568*a(n-12) +808526872576*a(n-13) +1304252383232*a(n-14) -1133951057920*a(n-15) +395539644416*a(n-16) -52613349376*a(n-17) for n>18

A208257 Number of nX7 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.

Original entry on oeis.org

365, 393216, 415737216, 439026252912, 463586569433280, 489518751475118880, 516901401841519506624, 545815772261840889783840, 576347550907375513255891248, 608587212579607572737693478288
Offset: 1

Views

Author

R. H. Hardin Feb 24 2012

Keywords

Comments

Column 7 of A208258

Examples

			Some solutions for n=4
..0..1..2..1..1..1..0....0..1..0..2..1..2..2....0..0..0..0..1..1..1
..1..2..0..1..2..2..1....1..2..0..1..2..0..0....2..0..1..2..0..2..1
..0..0..1..2..1..0..2....2..0..1..2..0..1..0....1..1..2..0..1..0..0
..1..2..2..0..0..2..1....1..2..0..1..2..2..0....0..2..1..2..1..2..0
		

Formula

Empirical: a(n) = 1373*a(n-1) -382385*a(n-2) +54747930*a(n-3) -5050986386*a(n-4) +332267679041*a(n-5) -16472142082703*a(n-6) +636007583672478*a(n-7) -19508251954601454*a(n-8) +480569383283952657*a(n-9) -9546208348531626993*a(n-10) +152598952268814061851*a(n-11) -1946846244225175080346*a(n-12) +19518911243309328077698*a(n-13) -150002896733353526035184*a(n-14) +849776274453519925228352*a(n-15) -3327166677806732426576264*a(n-16) +7899544532604413646690344*a(n-17) -6508673827964553701633600*a(n-18) -20940104457639861466791296*a(n-19) +72463799516214011378881024*a(n-20) -61429017906552923870936064*a(n-21) -129536619155578798140518400*a(n-22) +380737956559758296779800576*a(n-23) -211491273596407625450717184*a(n-24) -649598231455057371522924544*a(n-25) +1411628961483792374550233088*a(n-26) -535856510128456063711707136*a(n-27) -2479363142583076923579039744*a(n-28) +5970652384046936507902066688*a(n-29) -7499573050858256420655071232*a(n-30) +6280307951272279750928760832*a(n-31) -3675985493399257320121171968*a(n-32) +1481320042982141475269115904*a(n-33) -383743024338594997911683072*a(n-34) +54171200367877184095780864*a(n-35) -2546711369956156422225920*a(n-36) for n>37
Showing 1-6 of 6 results.