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 1-5 of 5 results.

A240039 T(n,k)=Number of nXk 0..2 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest, modulo 3.

Original entry on oeis.org

2, 2, 2, 4, 2, 4, 4, 6, 6, 4, 8, 4, 16, 4, 8, 8, 10, 16, 16, 10, 8, 16, 8, 42, 18, 42, 8, 16, 16, 20, 44, 52, 52, 44, 20, 16, 32, 16, 114, 62, 154, 62, 114, 16, 32, 32, 40, 122, 162, 178, 178, 162, 122, 40, 32, 64, 32, 314, 204, 494, 282, 494, 204, 314, 32, 64, 64, 80, 340, 530, 600
Offset: 1

Views

Author

R. H. Hardin, Mar 31 2014

Keywords

Comments

Table starts
..2..2...4...4....8....8....16....16....32.....32.....64.....64.....128.....128
..2..2...6...4...10....8....20....16....40.....32.....80.....64.....160.....128
..4..6..16..16...42...44...114...122...314....340....872....950....2432....2658
..4..4..16..18...52...62...162...204...530....672...1736...2198....5706....7202
..8.10..42..52..154..178...494...600..1606...2014...5262...6690...17464...22360
..8..8..44..62..178..282...710..1074..2770...4162..10836..15764...41374...59680
.16.20.114.162..494..710..1976..2884..7958..12074..31824..49078..130758..197208
.16.16.122.204..600.1074..2884..5706.14686..25224..66774.113794..307698..508002
.32.40.314.530.1606.2770..7958.14686.42470..72446.200916.360716..984770.1730698
.32.32.340.672.2014.4162.12074.25224.72446.147092.407954.778294.2194512.4046228

Examples

			Some solutions for n=3 k=4
..2..1..1..2....2..1..2..1....2..1..2..1....1..2..1..2....1..2..1..2
..1..0..0..0....1..0..0..0....1..0..0..0....2..0..0..0....2..0..0..0
..1..0..0..0....1..0..0..0....2..0..0..0....2..0..0..0....2..0..0..1
		

Crossrefs

Column 1 is A016116(n+1)
Column 2 is A163888(n-2) for n>3

Formula

Empirical for column k:
k=1: a(n) = 2*a(n-2)
k=2: a(n) = 2*a(n-2) for n>5
k=3: a(n) = 4*a(n-2) -3*a(n-4) -a(n-6) for n>7
k=4: [order 24] for n>27
k=5: [order 86] for n>89

A163609 a(n) = ((5 + 2*sqrt(2))*(3 + sqrt(2))^n + (5 - 2*sqrt(2))*(3 - sqrt(2))^n)/2.

Original entry on oeis.org

5, 19, 79, 341, 1493, 6571, 28975, 127853, 564293, 2490787, 10994671, 48532517, 214232405, 945666811, 4174374031, 18426576509, 81338840837, 359047009459, 1584910170895, 6996131959157, 30882420558677, 136321599637963
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Aug 01 2009

Keywords

Comments

Binomial transform of A163608. Third binomial transform of A163888. Inverse binomial transform of A163610.

Crossrefs

Programs

  • Magma
    Z:= PolynomialRing(Integers()); N:=NumberField(x^2-2); S:=[ ((5+2*r)*(3+r)^n+(5-2*r)*(3-r)^n)/2: n in [0..21] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Aug 06 2009
    
  • Mathematica
    LinearRecurrence[{6, -7}, {5, 19}, 50] (* G. C. Greubel, Jul 29 2017 *)
  • PARI
    x='x+O('x^50); Vec((5-11*x)/(1-6*x+7*x^2)) \\ G. C. Greubel, Jul 29 2017

Formula

a(n) = 6*a(n-1) - 7*a(n-2) for n > 1; a(0) = 5, a(1) = 19.
G.f.: (5-11*x)/(1-6*x+7*x^2).
a(n) = 5*A081179(n+1) - 11*A081179(n). - R. J. Mathar, Nov 08 2013
E.g.f.: exp(3*x)*( 5*cosh(sqrt(2)*x) + 2*sqrt(2)*sinh(sqrt(2)*x) ). - G. C. Greubel, Jul 29 2017

Extensions

Edited and extended beyond a(5) by Klaus Brockhaus, Aug 06 2009

A163610 a(n) = ((5 + 2*sqrt(2))*(4 + sqrt(2))^n + (5 - 2*sqrt(2))*(4 - sqrt(2))^n)/2.

Original entry on oeis.org

5, 24, 122, 640, 3412, 18336, 98920, 534656, 2892368, 15653760, 84736928, 458742784, 2483625280, 13446603264, 72802072192, 394164131840, 2134084044032, 11554374506496, 62557819435520, 338701312393216, 1833801027048448
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Aug 01 2009

Keywords

Comments

Binomial transform of A163609. Fourth binomial transform of A163888. Inverse binomial transform of A163611.

Crossrefs

Programs

  • Magma
    Z:= PolynomialRing(Integers()); N:=NumberField(x^2-2); S:=[ ((5+2*r)*(4+r)^n+(5-2*r)*(4-r)^n)/2: n in [0..20] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Aug 06 2009
    
  • Mathematica
    LinearRecurrence[{8,-14},{5,24},30] (* Harvey P. Dale, May 29 2016 *)
  • PARI
    x='x+O('x^50); Vec((5-16*x)/(1-8*x+14*x^2)) \\ G. C. Greubel, Jul 29 2017

Formula

a(n) = 8*a(n-1) - 14*a(n-2) for n > 1; a(0) = 5, a(1) = 24.
G.f.: (5-16*x)/(1-8*x+14*x^2).
E.g.f.: exp(4*x)*( 5*cosh(sqrt(2)*x) + 2*sqrt(2)*sinh(sqrt(2)*x) ). - G. C. Greubel, Jul 29 2017

Extensions

Edited and extended beyond a(5) by Klaus Brockhaus, Aug 06 2009

A163607 a(n) = ((5 + 2*sqrt(2))*(1 + sqrt(2))^n + (5 - 2*sqrt(2))*(1 - sqrt(2))^n)/2.

Original entry on oeis.org

5, 9, 23, 55, 133, 321, 775, 1871, 4517, 10905, 26327, 63559, 153445, 370449, 894343, 2159135, 5212613, 12584361, 30381335, 73347031, 177075397, 427497825, 1032071047, 2491639919, 6015350885, 14522341689, 35060034263, 84642410215
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Aug 01 2009

Keywords

Comments

Binomial transform of A163888. Inverse binomial transform of A163608.

Crossrefs

Programs

  • Magma
    Z:= PolynomialRing(Integers()); N:=NumberField(x^2-2); S:=[ ((5+2*r)*(1+r)^n+(5-2*r)*(1-r)^n)/2: n in [0..27] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Aug 06 2009
    
  • Mathematica
    LinearRecurrence[{2, 1}, {5, 9}, 50] (* G. C. Greubel, Jul 29 2017 *)
  • PARI
    x='x+O('x^50); Vec((5-x)/(1-2*x-x^2)) \\ G. C. Greubel, Jul 29 2017

Formula

a(n) = 2*a(n-1) + a(n-2) for n > 1; a(0) = 5, a(1) = 9.
G.f.: (5-x)/(1-2*x-x^2).
a(n) = 5*A000129(n+1) - A000129(n). - R. J. Mathar, Nov 08 2013
E.g.f.: exp(x)*( 5*cosh(sqrt(2)*x) + 2*sqrt(2)*sinh(sqrt(2)*x) ). - G. C. Greubel, Jul 29 2017
a(n) = 2*A001333(n) + A001333(n+2). - Philippe Deléham, Mar 06 2023

Extensions

Edited and extended beyond a(5) by Klaus Brockhaus, Aug 06 2009

A163611 a(n) = ((5 + 2*sqrt(2))*(5 + sqrt(2))^n + (5 - 2*sqrt(2))*(5 - sqrt(2))^n)/2.

Original entry on oeis.org

5, 29, 175, 1083, 6805, 43141, 274895, 1756707, 11244485, 72040589, 461782735, 2960893803, 18987935125, 121778793781, 781065429935, 5009742042387, 32132915535365, 206105088378749, 1321993826474095, 8479521232029723
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Aug 01 2009

Keywords

Comments

Binomial transform of A163610. Fifth binomial transform of A163888.

Crossrefs

Programs

  • Magma
    Z:= PolynomialRing(Integers()); N:=NumberField(x^2-2); S:=[ ((5+2*r)*(5+r)^n+(5-2*r)*(5-r)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Aug 06 2009
    
  • Mathematica
    LinearRecurrence[{10, -23}, {5, 29}, 50] (* G. C. Greubel, Jul 29 2017 *)
  • PARI
    x='x+O('x^50); Vec((5-21*x)/(1-10*x+23*x^2)) \\ G. C. Greubel, Jul 29 2017

Formula

a(n) = 10*a(n-1) - 23*a(n-2) for n > 1; a(0) = 5, a(1) = 29.
G.f.: (5-21*x)/(1-10*x+23*x^2).
E.g.f.: exp(5*x)*( 5*cosh(sqrt(2)*x) + 2*sqrt(2)*sinh(sqrt(2)*x) ). - G. C. Greubel, Jul 29 2017

Extensions

Edited and extended beyond a(5) by Klaus Brockhaus, Aug 06 2009
Showing 1-5 of 5 results.