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 1-10 of 30 results. Next

A152927 Number of sets (in the Hausdorff metric geometry) at each location between two sets defining a polygonal configuration consisting of k 4-gonal polygonal components chained with string components of length 1 as k varies.

Original entry on oeis.org

7, 113, 1815, 29153, 468263, 7521361, 120810039, 1940481985, 31168521799, 500636830769
Offset: 1

Views

Author

Steven Schlicker, Dec 15 2008

Keywords

Crossrefs

Programs

  • Maple
    with(combinat): a := proc(n) local aa, b, c, d, lambda, delta, R, S, F, L, m, l: m:=2: l:=1: F := n -> fibonacci(n): L := n -> fibonacci(n-1)+fibonacci(n+1): aa := (m, l) -> L(2*m)*F(l-2)+F(2*m+2)*F(l-1): b := (m, l) -> L(2*m)*F(l-1)+F(2*m+2)*F(l): c := (m, l) -> F(2*m+2)*F(l-2)+F(m+2)^2*F(l-1): d := (m, l) -> F(2*m+2)*F(l-1)+F(m+2)^2*F(l): lambda := (m,l) -> (d(m, l)+aa(m, l)+sqrt((d(m, l)-aa(m, l))^2+4*b(m, l)*c(m, l)))*(1/2): delta := (m,l) -> (d(m, l)+aa(m, l)-sqrt((d(m, l)-aa(m, l))^2+4*b(m, l)*c(m, l)))*(1/2): R := (m,l) -> ((lambda(m, l)-d(m, l))*L(2*m)+b(m, l)*F(2*m+2))/(2*lambda(m, l)-d(m, l)-aa(m, l)): S := (m,l) -> ((lambda(m, l)-aa(m, l))*L(2*m)-b(m, l)*F(2*m+2))/(2*lambda(m, l)-d(m, l)-aa(m, l)): simplify(R(m, l)*lambda(m, l)^(n-1)+S(m, l)*delta(m, l)^(n-1)); end proc;

Formula

Conjectures from Colin Barker, Jul 09 2020: (Start)
G.f.: x*(7 + x) / (1 - 16*x - x^2).
a(n) = 16*a(n-1) + a(n-2) for n>2.
(End)

A152928 Number of sets (in the Hausdorff metric geometry) at each location between two sets defining a polygonal configuration consisting of two m-gonal polygonal components chained with string components of length 1 as m varies.

Original entry on oeis.org

113, 765, 5234, 35865, 245813, 1684818, 11547905, 79150509, 542505650, 3718389033, 25486217573, 174685133970, 1197309720209, 8206482907485, 56248070632178, 385530011517753, 2642462009992085, 18111704058426834, 124139466398995745, 850864560734543373
Offset: 2

Views

Author

Steven Schlicker, Dec 15 2008

Keywords

Crossrefs

Programs

  • Maple
    with(combinat): a := proc(n) local aa, b, c, d, lambda, delta, Q, F, L:  F := fibonacci: L := t -> fibonacci(t-1)+fibonacci(t+1): aa := L(2*n)*F(l-2)+F(2*n+2)*F(l-1): b := L(2*n)*F(l-1)+F(2*n+2)*F(l): c :=  F(2*n+2)*F(l-2)+F(n+2)^2*F(l-1): d := F(2*n+2)*F(l-1)+F(n+2)^2*F(l): Q:=sqrt((d-aa)^2+4*b*c); lambda := (d+aa+Q)/2: delta := (d+aa-Q)/2: : simplify(lambda*((lambda-d)*L(2*n)+b*F(2*n+2))/Q+delta*((lambda-aa)*L(2*n)-b*F(2*n+2))/Q); end proc; # Simplified by M. F. Hasler, Apr 16 2015
  • Mathematica
    LinearRecurrence[{8, -8, 1}, {113, 765, 5234}, 30] (* Paolo Xausa, Jul 22 2024 *)
  • PARI
    Vec(x^2*(113 - 139*x + 18*x^2) / ((1 - x)*(1 - 7*x + x^2)) + O(x^20)) \\ Colin Barker, Aug 05 2020

Formula

G.f.: x^2*(113 - 139*x + 18*x^2)/(1 - 8*x + 8*x^2 - x^3). - M. F. Hasler, Apr 16 2015
a(n) = 8*a(n-1) - 8*a(n-2) + a(n-3) for n>4. - Colin Barker, Aug 05 2020

Extensions

More terms from M. F. Hasler, Apr 16 2015

A152929 Number of sets (in the Hausdorff metric geometry) at each location between two sets defining a polygonal configuration consisting of two 4-gonal polygonal components chained with string components of length l as l varies.

Original entry on oeis.org

113, 176, 289, 465, 754, 1219, 1973, 3192, 5165, 8357, 13522, 21879, 35401, 57280, 92681, 149961, 242642, 392603, 635245, 1027848, 1663093, 2690941, 4354034, 7044975, 11399009, 18443984, 29842993, 48286977, 78129970, 126416947, 204546917, 330963864, 535510781, 866474645
Offset: 1

Views

Author

Steven Schlicker, Dec 15 2008

Keywords

Crossrefs

Programs

  • Maple
    with(combinat): a := proc(n) local aa, b, c, d, lambda, delta, R, S, F, L4, Q: F := fibonacci: L4 := F(3)+F(5): aa := L4*F(n-2)+F(6)*F(n-1): b := L4*F(n-1)+F(6)*F(n): c := F(6)*F(n-2)+F(4)^2*F(n-1): d := F(6)*F(n-1)+F(4)^2*F(n): Q := sqrt((d-aa)^2+4*b*c); lambda := (d+aa+Q)/2: delta := (d+aa-Q)/2: R := ((lambda-d)*L4+b*F(6))/Q: S := ((lambda-aa)*L4-b*F(6))/Q: simplify(R*lambda+S*delta); end proc: # Simplified by M. F. Hasler, Apr 16 2015
  • Mathematica
    LinearRecurrence[{1, 1}, {113, 176}, 50] (* Paolo Xausa, Jul 23 2024 *)
  • PARI
    A152929(n)=50*fibonacci(n)+63*fibonacci(n+1) \\ M. F. Hasler, Apr 14 2015
    
  • PARI
    Vec(x*(113 + 63*x) / (1 - x - x^2) + O(x^30)) \\ Colin Barker, Aug 05 2020

Formula

a(n) = (163*A000045(n)+63*A000032(n))/2. - Conjectured by Philipp Emanuel Weidmann, cf. LINKS.
G.f.: x*(113 + 63*x)/(1 - x - x^2). - M. F. Hasler, Apr 16 2015
a(n) = a(n-1) + a(n-2) for n>2. - Colin Barker, Aug 05 2020
a(n) = Lucas(n+9) - Fibonacci(n+6) - Fibonacci(n-5). - Greg Dresden, Mar 14 2022

Extensions

More terms from M. F. Hasler, Apr 16 2015

A152930 Number of sets (in the Hausdorff metric geometry) at each location between two sets defining a polygonal configuration consisting of k 4-gonal polygonal components chained with string components of length 2 as k varies.

Original entry on oeis.org

7, 176, 4393, 109649, 2736832, 68311151, 1705041943, 42557737424, 1062238393657, 26513402104001, 661772814206368, 16517806953055199, 412283401012173607, 10290567218351284976, 256851897057769950793, 6411006859225897484849, 160018319583589667170432
Offset: 1

Views

Author

Steven Schlicker, Dec 15 2008

Keywords

Crossrefs

Programs

  • Maple
    with(combinat): a := proc(n) local aa, b, c, d, lambda, delta, R, S, F, L, m, l: m:=2: l:=2: F := n -> fibonacci(n): L := n -> fibonacci(n-1)+fibonacci(n+1): aa := (m, l) -> L(2*m)*F(l-2)+F(2*m+2)*F(l-1): b := (m, l) -> L(2*m)*F(l-1)+F(2*m+2)*F(l): c := (m, l) -> F(2*m+2)*F(l-2)+F(m+2)^2*F(l-1): d := (m, l) -> F(2*m+2)*F(l-1)+F(m+2)^2*F(l): lambda := (m,l) -> (d(m, l)+aa(m, l)+sqrt((d(m, l)-aa(m, l))^2+4*b(m, l)*c(m, l)))*(1/2): delta := (m,l) -> (d(m, l)+aa(m, l)-sqrt((d(m, l)-aa(m, l))^2+4*b(m, l)*c(m, l)))*(1/2): R := (m,l) -> ((lambda(m, l)-d(m, l))*L(2*m)+b(m, l)*F(2*m+2))/(2*lambda(m, l)-d(m, l)-aa(m, l)): S := (m,l) -> ((lambda(m, l)-aa(m, l))*L(2*m)-b(m, l)*F(2*m+2))/(2*lambda(m, l)-d(m, l)-aa(m, l)): simplify(R(m, l)*lambda(m, l)^(n-1)+S(m, l)*delta(m, l)^(n-1)); end proc;

Formula

Conjectures from Colin Barker, Jul 09 2020: (Start)
G.f.: x*(7 + x) / (1 - 25*x + x^2).
a(n) = 25*a(n-1) - a(n-2) for n>1.
(End)

A152931 Number of sets (in the Hausdorff metric geometry) at each location between two sets defining a polygonal configuration consisting of three m-gonal polygonal components chained with string components of length 2 as m varies.

Original entry on oeis.org

4393, 80361, 1425131, 25671393, 459934921, 8258011407, 148150698209, 2658683875329, 47706585218947, 856070631915129, 15361490875216193, 275651271699299271, 4946357927482614361, 88758815221749418713, 1592712152944203460571, 28580061055811939151057
Offset: 2

Views

Author

Steven Schlicker, Dec 15 2008

Keywords

Crossrefs

Programs

  • Maple
    with(combinat): a := proc(n) local aa, b, c, d, lambda, delta, R, S, F, L, k, l: k:=3: l:=2: F := t -> fibonacci(t): L := t -> fibonacci(t-1)+fibonacci(t+1): aa := (n, l) -> L(2*n)*F(l-2)+F(2*n+2)*F(l-1): b := (n, l) -> L(2*n)*F(l-1)+F(2*n+2)*F(l): c := (n, l) -> F(2*n+2)*F(l-2)+F(n+2)^2*F(l-1): d := (n, l) -> F(2*n+2)*F(l-1)+F(n+2)^2*F(l): lambda := (n,l) -> (d(n, l)+aa(n, l)+sqrt((d(n, l)-aa(n, l))^2+4*b(n, l)*c(n, l)))*(1/2): delta := (n,l) -> (d(n, l)+aa(n, l)-sqrt((d(n, l)-aa(n, l))^2+4*b(n, l)*c(n, l)))*(1/2): R := (n,l) -> ((lambda(n, l)-d(n, l))*L(2*n)+b(n, l)*F(2*n+2))/(2*lambda(n, l)-d(n, l)-aa(n, l)): S := (n,l) -> ((lambda(n, l)-aa(n, l))*L(2*n)-b(n, l)*F(2*n+2))/(2*lambda(n, l)-d(n, l)-aa(n, l)): simplify(R(n, l)*lambda(n, l)^(k-1)+S(n, l)*delta(n, l)^(k-1)); end proc;
  • Mathematica
    LinearRecurrence[{13,104,-260,-260,104,13,-1},{4393,80361,1425131,25671393,459934921,8258011407,148150698209},20] (* Harvey P. Dale, Feb 18 2024 *)

A152932 Number of sets (in the Hausdorff metric geometry) at each location between two sets defining a polygonal configuration consisting of three 6-gonal polygonal components chained with string components of length l as l varies.

Original entry on oeis.org

32733, 80361, 215658, 559305, 1469565, 3842082, 10063989, 26342577, 68971050, 180563265, 472726053, 1237607586, 3240104013, 8482697145, 22207994730, 58141279737, 152215851789, 398506268322, 1043302960485, 2731402605825, 7150904864298, 18721311979761
Offset: 1

Views

Author

Steven Schlicker, Dec 15 2008

Keywords

Crossrefs

Programs

  • Maple
    with(combinat): a := proc(n) local aa, b, c, d, lambda, delta, R, S, F, L, k, m: k:=3: m:=3: F := t -> fibonacci(t): L := t -> fibonacci(t-1)+fibonacci(t+1): aa := (m, n) -> L(2*m)*F(n-2)+F(2*m+2)*F(n-1): b := (m, n) -> L(2*m)*F(n-1)+F(2*m+2)*F(n): c := (m, n) -> F(2*m+2)*F(n-2)+F(m+2)^2*F(n-1): d := (m, n) -> F(2*m+2)*F(n-1)+F(m+2)^2*F(n): lambda := (m,n) -> (d(m, n)+aa(m, n)+sqrt((d(m, n)-aa(m, n))^2+4*b(m, n)*c(m, n)))*(1/2): delta := (m,n) -> (d(m, n)+aa(m, n)-sqrt((d(m, n)-aa(m, n))^2+4*b(m, n)*c(m, n)))*(1/2): R := (m,n) -> ((lambda(m, n)-d(m, n))*L(2*m)+b(m, n)*F(2*m+2))/(2*lambda(m, n)-d(m, n)-aa(m, n)): S := (m,n) -> ((lambda(m, n)-aa(m, n))*L(2*m)-b(m, n)*F(2*m+2))/(2*lambda(m, n)-d(m, n)-aa(m, n)): simplify(R(m, n)*lambda(m, n)^(k-1)+S(m, n)*delta(m, n)^(k-1)); end proc;

Formula

Conjectures from Colin Barker, Jul 09 2020: (Start)
G.f.: 9*x*(3637 + 1655*x - 1170*x^2) / ((1 + x)*(1 - 3*x + x^2)).
a(n) = 2*a(n-1) + 2*a(n-2) - a(n-3) for n>3.
(End)

A152933 Number of sets (in the Hausdorff metric geometry) at each location between two sets defining a polygonal configuration consisting of k 6-gonal polygonal components chained with string components of length 2 as k varies.

Original entry on oeis.org

18, 1197, 80361, 5394960, 362185569, 24314987763, 1632363850242, 109587212856081, 7357034536009605, 493907598828348264, 33158022432323420133, 2226032671355124283287, 149442611182684237761426, 10032689243282040048565125, 673535162800540841393716209
Offset: 1

Views

Author

Steven Schlicker, Dec 15 2008

Keywords

Crossrefs

Programs

  • Maple
    with(combinat): a := proc(n) local aa, b, c, d, lambda, delta, R, S, F, L, m, l: m:=3: l:=2: F := n -> fibonacci(n): L := n -> fibonacci(n-1)+fibonacci(n+1): aa := (m, l) -> L(2*m)*F(l-2)+F(2*m+2)*F(l-1): b := (m, l) -> L(2*m)*F(l-1)+F(2*m+2)*F(l): c := (m, l) -> F(2*m+2)*F(l-2)+F(m+2)^2*F(l-1): d := (m, l) -> F(2*m+2)*F(l-1)+F(m+2)^2*F(l): lambda := (m,l) -> (d(m, l)+aa(m, l)+sqrt((d(m, l)-aa(m, l))^2+4*b(m, l)*c(m, l)))*(1/2): delta := (m,l) -> (d(m, l)+aa(m, l)-sqrt((d(m, l)-aa(m, l))^2+4*b(m, l)*c(m, l)))*(1/2): R := (m,l) -> ((lambda(m, l)-d(m, l))*L(2*m)+b(m, l)*F(2*m+2))/(2*lambda(m, l)-d(m, l)-aa(m, l)): S := (m,l) -> ((lambda(m, l)-aa(m, l))*L(2*m)-b(m, l)*F(2*m+2))/(2*lambda(m, l)-d(m, l)-aa(m, l)): simplify(R(m, l)*lambda(m, l)^(n-1)+S(m, l)*delta(m, l)^(n-1)); end proc;

Formula

Conjectures from Colin Barker, Jul 09 2020: (Start)
G.f.: 9*x*(2 - x) / (1 - 67*x - 9*x^2).
a(n) = 67*a(n-1) + 9*a(n-2) for n>2.
(End)

A152934 Number of sets (in the Hausdorff metric geometry) at each location between two sets defining a polygonal configuration consisting of two m-gonal polygonal components chained with string components of length 3 as m varies.

Original entry on oeis.org

289, 1962, 13429, 92025, 630730, 4323069, 29630737, 203092074, 1392013765, 9541004265, 65395016074, 448224108237, 3072173741569, 21056992082730, 144326770837525, 989230403779929, 6780286055621962, 46472771985573789, 318529117843394545, 2183231052918188010
Offset: 2

Views

Author

Steven Schlicker, Dec 15 2008

Keywords

Crossrefs

Programs

  • Maple
    with(combinat): a := proc(n) local aa, b, c, d, lambda, delta, R, S, F, L, k, l: k:=2: l:=3: F := t -> fibonacci(t): L := t -> fibonacci(t-1)+fibonacci(t+1): aa := (n, l) -> L(2*n)*F(l-2)+F(2*n+2)*F(l-1): b := (n, l) -> L(2*n)*F(l-1)+F(2*n+2)*F(l): c := (n, l) -> F(2*n+2)*F(l-2)+F(n+2)^2*F(l-1): d := (n, l) -> F(2*n+2)*F(l-1)+F(n+2)^2*F(l): lambda := (n,l) -> (d(n, l)+aa(n, l)+sqrt((d(n, l)-aa(n, l))^2+4*b(n, l)*c(n, l)))*(1/2): delta := (n,l) -> (d(n, l)+aa(n, l)-sqrt((d(n, l)-aa(n, l))^2+4*b(n, l)*c(n, l)))*(1/2): R := (n,l) -> ((lambda(n, l)-d(n, l))*L(2*n)+b(n, l)*F(2*n+2))/(2*lambda(n, l)-d(n, l)-aa(n, l)): S := (n,l) -> ((lambda(n, l)-aa(n, l))*L(2*n)-b(n, l)*F(2*n+2))/(2*lambda(n, l)-d(n, l)-aa(n, l)): simplify(R(n, l)*lambda(n, l)^(k-1)+S(n, l)*delta(n, l)^(k-1)); end proc;

Formula

Conjectures from Colin Barker, Jul 09 2020: (Start)
G.f.: x^2*(289 - 350*x + 45*x^2) / ((1 - x)*(1 - 7*x + x^2)).
a(n) = 8*a(n-1) - 8*a(n-2) + a(n-3) for n>4.
(End)

A152683 Decimal expansion of log_6 (2).

Original entry on oeis.org

3, 8, 6, 8, 5, 2, 8, 0, 7, 2, 3, 4, 5, 4, 1, 5, 8, 6, 8, 7, 0, 2, 4, 6, 1, 3, 8, 4, 6, 7, 8, 2, 0, 8, 7, 6, 4, 6, 5, 1, 4, 1, 8, 5, 9, 4, 5, 7, 1, 0, 3, 4, 2, 8, 3, 8, 9, 4, 9, 4, 9, 2, 8, 8, 2, 6, 6, 4, 2, 0, 1, 8, 5, 4, 0, 7, 2, 2, 8, 0, 3, 8, 3, 1, 6, 5, 2
Offset: 0

Views

Author

N. J. A. Sloane, Oct 30 2009

Keywords

Comments

The upper bound for the ratio of the number of 3x+1 steps to all steps in the Collatz iteration. - T. D. Noe, Apr 30 2010

Examples

			.38685280723454158687024613846782087646514185945710342838949...
		

Crossrefs

Cf. decimal expansion of log_6(m): this sequence, A152935 (m=3), A153102 (m=4), A153202 (m=5), A153617 (m=7), A153754 (m=8), A154009 (m=9), A154157 (m=10), A154178 (m=11), A154199 (m=12), A154278 (m=13), A154466 (m=14), A154567 (m=15), A154776 (m=16), A154856 (m=17), A154911 (m=18), A155044 (m=19), A155490 (m=20), A155554 (m=21), A155697 (m=22), A155823 (m=23), A155959 (m=24).

Programs

  • Magma
    SetDefaultRealField(RealField(100)); Log(2)/Log(6); // G. C. Greubel, Sep 13 2018
  • Mathematica
    RealDigits[Log[6,2],10,120][[1]] (* Harvey P. Dale, Sep 12 2012 *)
  • PARI
    default(realprecision, 100); log(2)/log(6) \\ G. C. Greubel, Sep 13 2018
    

Formula

Equals log(2)/log(6) (A002162/A016629), that is, log(2)/(log(2)+log(3)). - Michel Marcus, Aug 18 2018

A154157 Decimal expansion of log_6 (10).

Original entry on oeis.org

1, 2, 8, 5, 0, 9, 7, 2, 0, 8, 9, 3, 8, 4, 6, 8, 7, 5, 9, 9, 4, 3, 4, 7, 9, 0, 9, 6, 5, 5, 4, 2, 8, 9, 5, 4, 8, 7, 1, 5, 7, 3, 3, 2, 1, 3, 2, 8, 1, 7, 5, 1, 2, 2, 7, 8, 7, 0, 1, 9, 3, 9, 1, 8, 0, 6, 9, 9, 9, 3, 1, 9, 3, 6, 1, 6, 8, 6, 2, 4, 3, 4, 1, 4, 6, 3, 3
Offset: 1

Views

Author

N. J. A. Sloane, Oct 30 2009

Keywords

Examples

			1.2850972089384687599434790965542895487157332132817512278701...
		

Crossrefs

Cf. decimal expansion of log_6(m): A152683 (m=2), A152935 (m=3), A153102 (m=4), A153202 (m=5), A153617 (m=7), A153754 (m=8), A154009 (m=9), this sequence, A154178 (m=11), A154199 (m=12), A154278 (m=13), A154466 (m=14), A154567 (m=15), A154776 (m=16), A154856 (m=17), A154911 (m=18), A155044 (m=19), A155490 (m=20), A155554 (m=21), A155697 (m=22), A155823 (m=23), A155959 (m=24).

Programs

  • Magma
    SetDefaultRealField(RealField(100)); Log(10)/Log(6); // G. C. Greubel, Sep 14 2018
  • Mathematica
    RealDigits[Log[6, 10], 10, 100][[1]] (* Vincenzo Librandi, Aug 31 2013 *)
  • PARI
    default(realprecision, 100); log(10)/log(6) \\ G. C. Greubel, Sep 14 2018
    
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