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.

A058860 Number of 2-connected rooted cubic planar maps with n faces.

Original entry on oeis.org

1, 3, 19, 128, 909, 6737, 51683, 407802, 3293497, 27122967, 227095683, 1928656876, 16582719509, 144125955717, 1264625068163, 11190598332502, 99776445196977, 895685185070155, 8090065969366259, 73480719648381240, 670821169614526749
Offset: 4

Views

Author

N. J. A. Sloane, Jan 06 2001; revised Feb 17 2006

Keywords

Examples

			G.f. = x^4 + 3*x^5 + 19*x^6 + 128*x^7 + 909*x^8 + 6737*x^9 + 51683*x^10 + ... - _Michael Somos_, Jul 22 2018
		

Crossrefs

Programs

  • Maple
    eq:=16*x^2*f^3+(8*x^4+24*x^3+72*x^2+8*x)*f^2+(x^6+6*x^5-5*x^4-40*x^3+3*x^2-14*x+1)*f-x^4-3*x^3+13*x^2-x: f:=sum(A[j]*x^j,j=1..35): for n from 1 to 35 do A[n]:=solve(coeff(expand(eq),x^n)=0) od: C2:=x^2*(f-x)*(1-2*x)/(1+x): C2ser:=series(C2,x=0,30): seq(coeff(C2ser,x^n),n=4..26); # Emeric Deutsch, Nov 30 2005
  • PARI
    F = x^2*(z - x)*(1 - 2*x)/(1 + x);
    G = 16*x^4*z^3 + x*(8*x^4 + 24*x^3 + 72*x^2 + 8*x)*z^2 + (x^6 + 6*x^5 -5*x^4 -40*x^3 + 3*x^2 - 14*x + 1)*z - x^3 - 3*x^2 + 13*x - 1;
    Z(N) = {
      my(z0 = 1 + O('x^N), z1=0, n=1);
      while (n++,
        z1 = z0 - subst(G, 'z, z0)/subst(deriv(G, 'z), 'z, z0);
        if (z1 == z0, break()); z0 = z1); z0;
    };
    seq(N) = Vec(subst(F, 'z, 'x*Z(N+1)));
    seq(21)
    \\ test: y=Ser(seq(303),'x)*x^4; 0 == 16*y^3 - 8*x*(2*x - 1)*(x^2 + 8*x + 1)*y^2 + x^2*(2*x - 1)^2*(x^4 + 20*x^3 + 50*x^2 - 16*x + 1)*y - x^6*(2*x - 1)^3*(x^2 + 11*x - 1)
    \\ Gheorghe Coserea, Jul 14 2018

Formula

G.f.: x^2*(f-x)*(1-2*x)/(1+x), where f is defined by 16*x^2*f^3 + (8*x^4+24*x^3+72*x^2+8*x)*f^2 + (x^6+6*x^5-5*x^4-40*x^3+3*x^2-14*x+1)*f - x^4-3*x^3+13*x^2-x=0. - Emeric Deutsch, Nov 30 2005
From Gheorghe Coserea, Jul 14 2018: (Start)
G.f. y=A(x) satisfies:
0 = 16*y^3 - 8*x*(2*x - 1)*(x^2 + 8*x + 1)*y^2 + x^2*(2*x - 1)^2*(x^4 + 20*x^3 + 50*x^2 - 16*x + 1)*y - x^6*(2*x - 1)^3*(x^2 + 11*x - 1).
0 = x^3*(2*x - 1)^3*(x - 2)*(4*x - 5)*(2*x^2 + 10*x - 1)*y''' - x^2*(2*x - 1)^2*(96*x^5 + 188*x^4 - 1570*x^3 + 1791*x^2 - 481*x + 35)*y'' + 12*x*(2*x - 1)*(48*x^6 + 104*x^5 - 898*x^4 + 1186*x^3 - 514*x^2 + 95*x - 5)*y' - 6*(256*x^7 + 608*x^6 - 5456*x^5 + 8292*x^4 - 4962*x^3 + 1525*x^2 - 220*x + 10)*y.
(End)

Extensions

More terms from Emeric Deutsch, Nov 30 2005

A058861 Number of 3-connected rooted cubic planar maps with n faces and girth at least 4.

Original entry on oeis.org

0, 0, 1, 3, 12, 59, 313, 1713, 9559, 54189, 311460, 1812281, 10661303, 63336873, 379601353, 2293205687, 13953099573, 85451824382, 526431271347, 3260689089300, 20296848348929, 126918850161182, 796981464813540
Offset: 4

Views

Author

N. J. A. Sloane, Jan 06 2001; revised Feb 17 2006

Keywords

Comments

Number of 3-connected triangle-free rooted cubic maps with n faces.

Crossrefs

Programs

  • Maple
    eq:=(x^3-3*x^2+3*x-1)*g^4+(4*x^4-12*x^3+9*x^2+2*x-3)*g^3+(6*x^5-10*x^4-15*x^3+36*x^2-14*x-3)*g^2+(4*x^6+4*x^5-45*x^4+82*x^3-59*x^2+14*x-1)*g+x^7+5*x^6-8*x^5+x^4: g:=sum(A[j]*x^j,j=1..37): for n from 1 to 37 do A[n]:=solve(coeff(expand(eq),x^n)=0) od: C3:=x^2*(1-3*x)*g: C3ser:=series(C3,x=0,34): seq(coeff(C3ser,x^n),n=6..30); # Emeric Deutsch, Nov 30 2005
  • PARI
    F = x^2*(1 - 3*x)*z;
    G = x^12*(x - 1)^3*z^4 + x^8*(x - 1)^2*(2*x - 3)*(2*x + 1)*z^3 + x^4*(x - 1)*(6*x^4 - 4*x^3 - 19*x^2 + 17*x + 3)*z^2 + (4*x^6 + 4*x^5 - 45*x^4 + 82*x^3 - 59*x^2 + 14*x - 1)*z + (x^3 + 5*x^2 - 8*x + 1);
    Z(N) = {
      my(z0 = 1 + O('x^N), z1=0, n=1);
      while (n++,
        z1 = z0 - subst(G, 'z, z0)/subst(deriv(G, 'z), 'z, z0);
        if (z1 == z0, break()); z0 = z1); z0;
    };
    seq(N) = concat([0, 0], Vec(subst(F, 'z, 'x^4*Z(N))));
    seq(21)
    \\ test: y = Ser(seq(303))*'x^4; 0 == (x - 1)^3*y^4 - x^2*(x - 1)^2*(2*x - 3)*(2*x + 1)*(3*x - 1)*y^3 + x^4*(x - 1)*(3*x - 1)^2*(6*x^4 - 4*x^3 - 19*x^2 + 17*x + 3)*y^2 - x^6*(3*x - 1)^3*(4*x^6 + 4*x^5 - 45*x^4 + 82*x^3 - 59*x^2 + 14*x - 1)*y + x^12*(3*x - 1)^4*(x^3 + 5*x^2 - 8*x + 1)
    \\ Gheorghe Coserea, Jul 15 2018

Formula

G.f.: x^2*(1-3*x)*g, where g is defined by (x^3-3*x^2+3*x-1)*g^4 + (4*x^4-12*x^3+9*x^2+2*x-3)*g^3 + (6*x^5-10*x^4-15*x^3+36*x^2-14*x-3)*g^2 + (4*x^6+4*x^5-45*x^4+82*x^3-59*x^2+14*x-1)*g + x^7+5*x^6-8*x^5+x^4=0. - Emeric Deutsch, Nov 30 2005
From Gheorghe Coserea, Jul 15 2018: (Start)
G.f. y=A(x) satisfies:
0 = (x - 1)^3*y^4 - x^2*(x - 1)^2*(2*x - 3)*(2*x + 1)*(3*x - 1)*y^3 + x^4*(x - 1)*(3*x - 1)^2*(6*x^4 - 4*x^3 - 19*x^2 + 17*x + 3)*y^2 - x^6*(3*x - 1)^3*(4*x^6 + 4*x^5 - 45*x^4 + 82*x^3 - 59*x^2 + 14*x - 1)*y + x^12*(3*x - 1)^4*(x^3 + 5*x^2 - 8*x + 1).
0 = x^4*(x - 1)^3*(3*x - 1)^4*(256*x^3 - 512*x^2 + 256*x - 27)*(660*x^5 - 2668*x^4 + 4177*x^3 - 3252*x^2 + 1305*x - 220)*y'''' - 4*x^3*(x - 1)^2*(3*x - 1)^3*(696960*x^10 - 5684352*x^9 + 19870624*x^8 - 39218578*x^7 + 48478923*x^6 - 39311914*x^5 + 21210466*x^4 - 7501069*x^3 + 1650104*x^2 - 201370*x + 10395)*y''' + 4*x^2*(x - 1)*(3*x - 1)^2*(7579440*x^12 - 77500656*x^11 + 341548428*x^10 - 862746936*x^9 + 1396393806*x^8 - 1530275829*x^7 + 1167408906*x^6 - 625929723*x^5 + 234247228*x^4 - 59616890*x^3 + 9784582*x^2 - 931830*x + 38940)*y'' - 24*x*(3*x - 1)*(8523900*x^14 - 105292620*x^13 + 561229815*x^12 - 1731677190*x^11 + 3479254732*x^10 - 4837165728*x^9 + 4815815835*x^8 - 3498631418*x^7 + 1868972298*x^6 - 732379803*x^5 + 207693098*x^4 - 41430916*x^3 + 5510394*x^2 - 438095*x + 15730)*y' + 24*(27442800*x^15 - 372895380*x^14 + 2140330050*x^13 - 7047776880*x^12 + 15074631336*x^11 - 22357962673*x^10 + 23891962029*x^9 - 18825921582*x^8 + 11080006886*x^7 - 4892373579*x^6 + 1614037497*x^5 - 392156906*x^4 + 68130318*x^3 - 8004294*x^2 + 569210*x - 18480)*y.
(End)

Extensions

More terms from Emeric Deutsch, Nov 30 2005
Showing 1-2 of 2 results.