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 10 results.

A019497 Number of ternary search trees on n keys.

Original entry on oeis.org

1, 1, 1, 3, 6, 16, 42, 114, 322, 918, 2673, 7875, 23457, 70551, 213846, 652794, 2004864, 6190612, 19207416, 59850384, 187217679, 587689947, 1850692506, 5845013538, 18509607753, 58759391013, 186958014766, 596108115402, 1904387243796, 6095040222192, 19540540075824
Offset: 0

Views

Author

James Fill (jimfill(AT)jhu.edu)

Keywords

Links

Crossrefs

Cf. A137954, A137959, A137966.

Programs

  • Maple
    A:= proc(n) option remember; if n=0 then 1 else convert(series(1+x+x^2*A(n-1)^3, x=0,n+1), polynom) fi end: a:= n-> coeff(A(n), x,n): seq(a(n), n=0..27); # Alois P. Heinz, Aug 22 2008
  • Mathematica
    a[0] = 1; a[n_] := Sum[Binomial[1*(n-k), k]/(n-k)*Binomial[3*k, n-k-1], {k, 0, n-1}]; Table[a[n], {n, 0, 27}] (* Jean-François Alcover, Apr 07 2015, after Paul D. Hanna *)
  • PARI
    v=vector(50,j,1);for(n=3,50,A=sum(i=1,n,sum(j=1,n,sum(k=1,n,if(i+j+k-n,0,v[i]*v[j]*v[k]))));v[n]=A);a(n)=v[n+1];
  • PARI
    {a(n)= local(A); if(n<0, 0, A= 1+O(x); forstep(k= 1, n, 2, A= 1+x+x*x*A^3); polcoeff(A, n))} /* Michael Somos, Mar 29 2007 */
  • PARI
    {a(n)= if(n<0, 0, (-1)^n* polcoeff( serreverse((1-sqrt(1-4*x+4*x^3+x^2*O(x^n)))/2), n+1))} /* Michael Somos, Mar 29 2007 */
  • PARI
    a(n)=if(n==0,1,sum(k=0,n-1,binomial(1*(n-k),k)/(n-k)*binomial(3*k,n-k-1))) \\ Paul D. Hanna, Jun 16 2009

Formula

a(0)=a(1)=1 and for n>=2 a(n)= sum( i+j+k=n-2, a(i)*a(j)*a(k) ) (i, j, k>=0). - Benoit Cloitre, Jun 14 2004
G.f. A(x) satisfies A(x)= 1+ x+ x^2*A(x)^3. - Michael Somos, Mar 29 2007
Given g.f. A(x), then x*A(-x) is series reversion of A025262(n-1). - Michael Somos, Mar 29 2007
a(n) = Sum_{k=0..n-1} C(n-k,k)/(n-k) * C(3*k,n-k-1) for n>0 with a(0)=1. - Paul D. Hanna, Jun 16 2009
a(n) ~ (8 + 3*sqrt(3))^(1/4) * 3^(n/2 - 3/8) * (3 + sqrt(9 + 8*sqrt(3)))^(n + 1/2) / (sqrt(Pi) * n^(3/2) * 2^(2*n + 2)). - Vaclav Kotesovec, Jul 31 2021

Extensions

More terms from Olivier Gérard, Jul 1997

A137953 G.f. satisfies A(x) = 1 + x*(1 + x*A(x)^2)^3.

Original entry on oeis.org

1, 1, 3, 9, 34, 132, 546, 2327, 10191, 45534, 206788, 951723, 4429182, 20808186, 98550468, 470038119, 2255684699, 10883852112, 52769785320, 256960840946, 1256147650818, 6162349332204, 30328107189312, 149698391878458
Offset: 0

Views

Author

Paul D. Hanna, Feb 26 2008

Keywords

Links

Crossrefs

Cf. A137952, A137954; A137957, A137962, A137969.

Programs

  • Mathematica
    Flatten[{1,Table[Sum[Binomial[3*(n-k), k]/(n-k)*Binomial[2*k, n-k-1],{k,0,n-1}],{n,1,20}]}] (* Vaclav Kotesovec after Paul D. Hanna, Mar 25 2014 *)
  • PARI
    {a(n)=local(A=1+x*O(x^n));for(i=0,n,A=1+x*(1+x*A^2)^3);polcoeff(A,n)}
  • PARI
    a(n)=if(n==0,1,sum(k=0,n-1,binomial(3*(n-k),k)/(n-k)*binomial(2*k,n-k-1))) \\ Paul D. Hanna, Jun 16 2009

Formula

G.f.: A(x) = 1 + x*B(x)^3 where B(x) is the g.f. of A137952.
a(n) = Sum_{k=0..n-1} C(3*(n-k),k)/(n-k) * C(2*k,n-k-1) for n>0 with a(0)=1. - Paul D. Hanna, Jun 16 2009
Recurrence: 5*n*(5*n-3)*(5*n-2)*(5*n+1)*(5*n+4)*(2948400*n^11 - 80922240*n^10 + 991552680*n^9 - 7191167904*n^8 + 34388915791*n^7 - 113938412552*n^6 + 266574560812*n^5 - 439214051186*n^4 + 497527715029*n^3 - 367402366838*n^2 + 158427508008*n - 30063700800)*a(n) = -240*(5*n-1)*(3402000*n^13 - 102564900*n^12 + 1682146080*n^11 - 16176231033*n^10 + 95359496344*n^9 - 359981654612*n^8 + 893831335718*n^7 - 1468770570635*n^6 + 1566970769558*n^5 - 1019176919948*n^4 + 331927521052*n^3 + 34505928*n^2 - 32180612832*n + 6541274880)*a(n-1) + 180*(884520000*n^16 - 26930232000*n^15 + 372745486800*n^14 - 3118060887120*n^13 + 17644263763548*n^12 - 71507400823524*n^11 + 214013670957835*n^10 - 480132169105811*n^9 + 810380315383846*n^8 - 1022562903644722*n^7 + 947982058983979*n^6 - 624324084479227*n^5 + 273663045967416*n^4 - 68343334466444*n^3 + 4273926176256*n^2 + 2065304121408*n - 381518968320)*a(n-2) + 72*(5890903200*n^16 - 188191699920*n^15 + 2743292998800*n^14 - 24248455085592*n^13 + 145518104758338*n^12 - 628264374415281*n^11 + 2014705595228766*n^10 - 4876859081303636*n^9 + 8950855221646414*n^8 - 12378944029917433*n^7 + 12665670452628658*n^6 - 9249292270917382*n^5 + 4496305419163048*n^4 - 1229711760456116*n^3 + 68797455703176*n^2 + 53468550934560*n - 10544040864000)*a(n-3) + 72*(5731689600*n^16 - 191702972160*n^15 + 2927459413440*n^14 - 27105381081216*n^13 + 170350803352728*n^12 - 770345146059408*n^11 + 2589617705669352*n^10 - 6581794624393248*n^9 + 12710327685293639*n^8 - 18531898603387194*n^7 + 20012311600272546*n^6 - 15421584075698196*n^5 + 7904537517669183*n^4 - 2290793383663938*n^3 + 159318295564312*n^2 + 94065554487360*n - 19593691084800)*a(n-4) + 72*(2*n-9)*(3*n-11)*(3*n-7)*(6*n-25)*(6*n-23)*(2948400*n^11 - 48489840*n^10 + 344492280*n^9 - 1422208584*n^8 + 3817772239*n^7 - 6909787807*n^6 + 8311308487*n^5 - 6272196721*n^4 + 2621759746*n^3 - 403021048*n^2 - 67705152*n + 22579200)*a(n-5). - Vaclav Kotesovec, Mar 25 2014
a(n) ~ sqrt(3*s*(s-1)*(3*s-2)/(5*s-3)) / (2*sqrt(Pi)*n^(3/2)*r^n), where s = 1.7888356349988794022183... is the root of the equation 216*(s-1)^2 = s*(5*s-6)^4, and r = 1/(s*(5*s-6)) = 0.189873988477346598... - Vaclav Kotesovec, Mar 25 2014

A137966 G.f. satisfies A(x) = 1+x + x^2*A(x)^6.

Original entry on oeis.org

1, 1, 1, 6, 21, 86, 396, 1812, 8607, 41958, 207333, 1040234, 5281965, 27078756, 140021248, 729369474, 3823598232, 20158251814, 106809280563, 568471343322, 3037782047947, 16292380484454, 87669285293451, 473172657154822
Offset: 0

Views

Author

Paul D. Hanna, Feb 26 2008

Keywords

Links

Crossrefs

Cf. A137967, A137965; A019497, A137954, A137959.

Programs

  • Mathematica
    Flatten[{1, Table[Sum[Binomial[n-k,k]/(n-k) * Binomial[6*k,n-k-1], {k,0,n-1}], {n,1,30}]}] (* Vaclav Kotesovec, Nov 18 2017 *)
  • PARI
    {a(n)=local(A=1+x*O(x^n));for(i=0,n,A=1+x*(1+x*A^6)^1);polcoeff(A,n)}
  • PARI
    a(n)=if(n==0,1,sum(k=0,n-1,binomial(n-k,k)/(n-k)*binomial(6*k,n-k-1))) \\ Paul D. Hanna, Jun 16 2009

Formula

a(n) = Sum_{k=0..n-1} C(n-k,k)/(n-k) * C(6*k,n-k-1) for n>0 with a(0)=1. - Paul D. Hanna, Jun 16 2009
Recurrence: 5*(n-1)*n*(5*n - 26)*(5*n - 21)*(5*n - 19)*(5*n - 16)*(5*n - 14)*(5*n - 12)*(5*n - 11)*(5*n - 9)*(5*n - 7)*(5*n - 6)*(5*n - 4)*(5*n - 2)*(5*n + 2)*a(n) = + 576*(n-1)^2*(3*n - 5)*(3*n - 4)*(3*n - 2)*(3*n - 1)*(5*n - 26)*(5*n - 21)*(5*n - 19)*(5*n - 16)*(5*n - 14)*(5*n - 12)*(5*n - 11)*(5*n - 9)*(5*n - 7)*a(n-2) + 288*(3*n - 5)*(3*n - 4)*(5*n - 26)*(5*n - 21)*(5*n - 19)*(5*n - 16)*(5*n - 14)*(5*n - 12)*(11250*n^7 - 111375*n^6 + 440175*n^5 - 888545*n^4 + 975241*n^3 - 574177*n^2 + 165869*n - 18018)*a(n-3) + 144*(5*n - 26)*(5*n - 21)*(5*n - 19)*(5*n - 6)*(10125000*n^11 - 218700000*n^10 + 2075585625*n^9 - 11378954250*n^8 + 39836289925*n^7 - 92894908470*n^6 + 145953551806*n^5 - 152681445300*n^4 + 102505633480*n^3 - 41086190160*n^2 + 8557182144*n - 670602240)*a(n-4) + 72*(5*n - 26)*(5*n - 11)*(5*n - 6)*(5*n - 4)*(20250000*n^11 - 569025000*n^10 + 7025658750*n^9 - 50083579125*n^8 + 227686012400*n^7 - 687547140050*n^6 + 1391232445598*n^5 - 1854143517725*n^4 + 1550931293540*n^3 - 737424345140*n^2 + 162058858752*n - 10360465920)*a(n-5) + 144*(5*n - 16)*(5*n - 11)*(5*n - 9)*(5*n - 6)*(5*n - 4)*(5*n - 2)*(202500*n^9 - 5953500*n^8 + 74924775*n^7 - 526434885*n^6 + 2255339082*n^5 - 6025054075*n^4 + 9796892735*n^3 - 8893818500*n^2 + 3545754268*n - 142331280)*a(n-6) + 72*n*(2*n - 9)*(3*n - 17)*(3*n - 10)*(5*n - 21)*(5*n - 16)*(5*n - 14)*(5*n - 11)*(5*n - 9)*(5*n - 7)*(5*n - 6)*(5*n - 4)*(5*n - 2)*(6*n - 41)*(6*n - 13)*a(n-7). - Vaclav Kotesovec, Nov 18 2017
a(n) ~ sqrt((1 + 2*r*s^6)/(15*Pi)) / (2*s^2 * n^(3/2) * r^(n + 1/2)), where r = 0.1734895129039028676461340698295316044509963479582... and s = 1.408187415484683441175360883795437925341195617549... are roots of the system of equations 1 + r + r^2*s^6 = s, 6*r^2*s^5 = 1. - Vaclav Kotesovec, Nov 18 2017

A137955 G.f. satisfies A(x) = 1 + x*(1 + x*A(x)^4)^2.

Original entry on oeis.org

1, 1, 2, 9, 36, 172, 842, 4310, 22676, 121896, 666884, 3699973, 20771096, 117765084, 673367034, 3878538930, 22483446152, 131070712924, 767929882240, 4519387797894, 26704456819984, 158367557278412, 942285096541344, 5623496055739052, 33653373190735484
Offset: 0

Views

Author

Paul D. Hanna, Feb 26 2008

Keywords

Links

Crossrefs

Cf. A137956, A137954; A137952, A137960, A137967.

Programs

  • Mathematica
    Flatten[{1,Table[Sum[Binomial[2*(n-k),k]/(n-k)*Binomial[4*k,n-k-1],{k,0,n-1}],{n,1,20}]}] (* Vaclav Kotesovec, Sep 18 2013 *)
  • PARI
    {a(n)=local(A=1+x*O(x^n));for(i=0,n,A=1+x*(1+x*A^4)^2);polcoeff(A,n)}
  • PARI
    a(n)=if(n==0,1,sum(k=0,n-1,binomial(2*(n-k),k)/(n-k)*binomial(4*k,n-k-1))) \\ Paul D. Hanna, Jun 16 2009

Formula

G.f.: A(x) = 1 + x*B(x)^2 where B(x) is the g.f. of A137956.
a(n) = Sum_{k=0..n-1} C(2*(n-k),k)/(n-k) * C(4*k,n-k-1) for n>0 with a(0)=1. - Paul D. Hanna, Jun 16 2009
a(n) ~ sqrt(2*s*(1-s)*(4-5*s) / ((56*s - 48)*Pi)) / (n^(3/2) * r^n), where r = 0.1569043698639381952962655091205241634381480571697... and s = 1.444765371242615455251538467189577278901629278244... are real roots of the system of equations s = 1 + r*(1 + r*s^4)^2, 8 * r^2 * s^3 * (1 + r*s^4) = 1. - Vaclav Kotesovec, Nov 22 2017

A137959 G.f. satisfies A(x) = 1 + x + x^2*A(x)^5.

Original entry on oeis.org

1, 1, 1, 5, 15, 55, 220, 876, 3645, 15485, 66735, 292155, 1293456, 5782320, 26071435, 118402495, 541150155, 2487204315, 11488482130, 53302256250, 248293549685, 1160794446445, 5444674773325, 25614768620105, 120837493137460
Offset: 0

Views

Author

Paul D. Hanna, Feb 26 2008

Keywords

Links

Crossrefs

Cf. A137960, A137958; A019497, A137954, A137966.

Programs

  • Mathematica
    Flatten[{1,Table[Sum[Binomial[n-k,k]/(n-k)*Binomial[5*k,n-k-1],{k,0,n-1}],{n,1,20}]}] (* Vaclav Kotesovec, Sep 18 2013 *)
  • PARI
    {a(n)=local(A=1+x*O(x^n));for(i=0,n,A=1+x*(1+x*A^5));polcoeff(A,n)}
  • PARI
    a(n)=if(n==0,1,sum(k=0,n-1,binomial(n-k,k)/(n-k)*binomial(5*k,n-k-1))) \\ Paul D. Hanna, Jun 16 2009

Formula

a(n) = Sum_{k=0..n-1} C(n-k,k)/(n-k) * C(5*k,n-k-1) for n>0 with a(0)=1. - Paul D. Hanna, Jun 16 2009
Recurrence: 64*(n-4)*(n-3)*(n-2)*(n-1)*n*(2*n-5)*(2*n-3)*(2*n-1)*(2*n+1)*a(n) = + 5*(n-4)*(n-3)*(n-2)*(2*n-5)*(2*n-3)*(5*n-8)*(5*n-6)*(5*n-4)*(5*n-2)*a(n-2) + 5*(n-4)*(n-3)*(2*n-5)*(5000*n^6 - 45000*n^5 + 157250*n^4 - 267750*n^3 + 227216*n^2 - 87057*n + 11520)*a(n-3) + 15*(n-4)*(5000*n^8 - 80000*n^7 + 532250*n^6 - 1903250*n^5 + 3938648*n^4 - 4710638*n^3 + 3044313*n^2 - 895443*n + 80640)*a(n-4) + 5*(n-2)*(2*n-1)*(5000*n^7 - 95000*n^6 + 734250*n^5 - 2951750*n^4 + 6510194*n^3 - 7505289*n^2 + 3655107*n - 207360)*a(n-5) + 5*(n-3)*(n-2)*n*(2*n-3)*(2*n-1)*(5*n-29)*(5*n-23)*(5*n-17)*(5*n-11)*a(n-6). - Vaclav Kotesovec, Sep 18 2013
a(n) ~ sqrt(s*(1-s)*(5-6*s) / ((40*s - 40)*Pi)) / (n^(3/2) * r^n), where r = 0.1990700277700792324868112833575428736312653553870... and s = 1.498837534712599040608514104196928592039081694233... are real roots of the system of equations s = 1 + r*(1 + r*s^5), 5 * r^2 * s^4 = 1. - Vaclav Kotesovec, Nov 22 2017

A366558 G.f. A(x) satisfies A(x) = 1 + x + x^4*A(x)^4.

Original entry on oeis.org

1, 1, 0, 0, 1, 4, 6, 4, 5, 28, 84, 140, 162, 304, 1018, 2644, 4760, 7364, 15540, 42680, 102059, 195904, 356542, 782880, 1950844, 4467288, 9011156, 17960676, 39984254, 94642292, 212395260, 444063984, 931300500, 2082762572, 4796413292, 10681800072, 22892593021
Offset: 0

Views

Author

Seiichi Manyama, Oct 13 2023

Keywords

Crossrefs

Cf. A137954, A366267, A366557.
Cf. A366554, A366556.
Cf. A366595.

Programs

  • PARI
    a(n) = sum(k=0, n\4, binomial(3*k+1, n-4*k)*binomial(4*k, k)/(3*k+1));

Formula

a(n) = Sum_{k=0..floor(n/4)} binomial(3*k+1,n-4*k) * binomial(4*k,k)/(3*k+1).
a(n) = A366595(n) + A366595(n-1).

A295404 G.f. A(x) satisfies: A(x) = A(x)^2 - x*A(x)^3 + x^2.

Original entry on oeis.org

1, 1, 1, 4, 10, 32, 95, 306, 978, 3235, 10767, 36470, 124514, 429648, 1492944, 5225700, 18396350, 65115694, 231555165, 826956617, 2964543205, 10664540170, 38484972969, 139281469165, 505408580484, 1838442927937, 6702466323520, 24486411113076, 89630823136513, 328680670354328, 1207323483992684, 4441801238353311, 16365832987077134, 60384021404260146, 223087697417538491
Offset: 0

Views

Author

Paul D. Hanna, Nov 21 2017

Keywords

Examples

			G.f.: A(x) =  1 + x + x^2 + 4*x^3 + 10*x^4 + 32*x^5 + 95*x^6 + 306*x^7 + 978*x^8 + 3235*x^9 + 10767*x^10 + 36470*x^11 + 124514*x^12 + 429648*x^13 + 1492944*x^14 + 5225700*x^15 + 18396350*x^16 + 65115694*x^17 + 231555165*x^18 + 826956617*x^19 + 2964543205*x^20 +...
such that A(x) = A(x)^2 - x*A(x)^3 + x^2.
RELATED SERIES.
1/A(x) = 1 - x - 3*x^3 - 3*x^4 - 16*x^5 - 32*x^6 - 121*x^7 - 329*x^8 - 1138*x^9 - 3546*x^10 - 12097*x^11 - 40112*x^12 +...
A(x)^2 = 1 + 2*x + 3*x^2 + 10*x^3 + 29*x^4 + 92*x^5 + 290*x^6 + 946*x^7 + 3114*x^8 + 10438*x^9 + 35332*x^10 + 120968*x^11 + 417551*x^12 +...
A(x)^3 = 1 + 3*x + 6*x^2 + 19*x^3 + 60*x^4 + 195*x^5 + 640*x^6 + 2136*x^7 + 7203*x^8 + 24565*x^9 + 84498*x^10 + 293037*x^11 + 1023184*x^12 +...
where A(x) = 1 + x*A(x)^2 - x^2/A(x).
Series_Reversion(x*A(x)) = x - x^2 + x^3 - 4*x^4 + 10*x^5 - 32*x^6 + 107*x^7 - 360*x^8 + 1270*x^9 - 4544*x^10 + 16537*x^11 - 61092*x^12 + 228084*x^13 - 860056*x^14 + 3269994*x^15 +...+ (-1)^(n-1)*A137954(n-1)*x^n +...

Links

Crossrefs

Cf. A137954.

Programs

  • PARI
    {a(n)=local(A=1+x); for(i=1, n, A = 1 + x*A^2 - x^2/A  +x*O(x^n)); polcoeff(G=A, n)}
for(n=0,40,print1(a(n),", "))

Formula

G.f. A(x) satisfies: A(x) = 1 + x*A(x)^2 - x^2/A(x).
a(n) ~ sqrt((s^3 - 2*r)/(Pi*(3*r*s - 1))) / (2*n^(3/2)*r^(n - 1/2)), where r = 0.2590976379022320530812109572925567785373263490686... and s = 1.89364715749587181948481325332597309754099061462... are real roots of the system of equations r^2 + s^2 = s + r*s^3, 1 + 3*r*s^2 = 2*s. - Vaclav Kotesovec, Nov 23 2017

A371607 G.f. satisfies A(x) = ( 1 + x * (1 + x*A(x)^2) )^2.

Original entry on oeis.org

1, 2, 3, 10, 29, 92, 314, 1078, 3830, 13844, 50746, 188554, 707667, 2679960, 10227940, 39294772, 151859858, 589943516, 2302462140, 9023681820, 35498194465, 140122652960, 554827907272, 2203135245820, 8771143399104, 35003747271444, 140002994665366
Offset: 0

Views

Author

Seiichi Manyama, Mar 29 2024

Keywords

Crossrefs

Cf. A137954, A371612.

Programs

  • PARI
    a(n, r=2, s=1, t=0, u=4) = r*sum(k=0, n, binomial(t*k+u*(n-k)+r, k)*binomial(s*k, n-k)/(t*k+u*(n-k)+r));

Formula

a(n) = Sum_{k=0..n} binomial(4*(n-k)+2,k) * binomial(k,n-k)/(2*(n-k)+1).
G.f.: A(x) = B(x)^2 where B(x) is the g.f. of A137954.

A366557 G.f. A(x) satisfies A(x) = 1 + x + x^3*A(x)^4.

Original entry on oeis.org

1, 1, 0, 1, 4, 6, 8, 29, 84, 162, 360, 1074, 2808, 6444, 16464, 45629, 118244, 297450, 790184, 2138438, 5624136, 14778068, 39767024, 107287122, 286593800, 768920084, 2083170960, 5642886852, 15250029552, 41369986008, 112681853344, 306930498205, 836259756612
Offset: 0

Views

Author

Seiichi Manyama, Oct 13 2023

Keywords

Crossrefs

Cf. A137954, A366267, A366558.
Cf. A366594.

Programs

  • PARI
    a(n) = sum(k=0, n\3, binomial(3*k+1, n-3*k)*binomial(4*k, k)/(3*k+1));

Formula

a(n) = Sum_{k=0..floor(n/3)} binomial(3*k+1,n-3*k) * binomial(4*k,k)/(3*k+1).
a(n) = A366594(n) + A366594(n-1).

A366593 G.f. A(x) satisfies A(x) = 1 + x^2*(1+x)^3*A(x)^4.

Original entry on oeis.org

1, 0, 1, 3, 7, 25, 82, 278, 992, 3552, 12985, 48107, 179977, 680079, 2589915, 9931573, 38319117, 148640195, 579349123, 2267818509, 8911575579, 35141656433, 139018921717, 551557089103, 2194155973751, 8750097458849, 34973989188202, 140085055366350
Offset: 0

Views

Author

Seiichi Manyama, Oct 14 2023

Keywords

Crossrefs

Cf. A366272, A366594, A366595.
Cf. A137954.

Programs

  • PARI
    a(n) = sum(k=0, n\2, binomial(3*k, n-2*k)*binomial(4*k, k)/(3*k+1));

Formula

a(n) = Sum_{k=0..floor(n/2)} binomial(3*k,n-2*k) * binomial(4*k,k)/(3*k+1).
Showing 1-10 of 10 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.