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 1-4 of 4 results.

A110153 Expansion of g.f.: Product_{n>=1} 1/(1 - 3^n*x^n)^(3/3^n).

Original entry on oeis.org

1, 3, 12, 39, 138, 426, 1461, 4458, 14655, 45309, 145479, 443037, 1427196, 4329696, 13655325, 41795679, 131102229, 397649811, 1247247507, 3775785681, 11761535064, 35770717695, 110693177805, 335003030301, 1040296817955, 3145674794979, 9695067728493, 29405519846121
Offset: 0

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Author

Paul D. Hanna, Jul 14 2005

Keywords

Examples

			A(x) = 1 + 3*x + 12*x^2 + 39*x^3 + 138*x^4 + 426*x^5 + ... =
  1/[(1-3*x)*(1-9*x^2)^(1/3)*(1-27*x^3)^(1/9)*(1-81*x^4)^(1/27)*...].
		

Crossrefs

Programs

  • Mathematica
    nmax=27; CoefficientList[Series[Product[1/(1 - 3^n*x^n)^(3/3^n),{n,nmax}],{x,0,nmax}],x] (* Stefano Spezia, Jun 21 2024 *)
  • PARI
    a(n)=polcoeff(prod(k=1,n,1/(1-3^k*x^k+x*O(x^n))^(3/3^k)),n)

Extensions

a(25)-a(27) from Stefano Spezia, Jun 21 2024

A110154 G.f.: A(x) = Product_{n>=1} 1/(1 - 4^n*x^n)^(4/4^n); self-convolution of A110156.

Original entry on oeis.org

1, 4, 20, 84, 380, 1540, 6796, 27380, 117020, 476260, 2002220, 8063316, 33957180, 136489156, 566211660, 2290272692, 9463603036, 38042178340, 157211980652, 631321594900, 2594532576636, 10457495255940, 42791736547980
Offset: 0

Views

Author

Paul D. Hanna, Jul 14 2005

Keywords

Examples

			A(x) = 1 + 4*x + 20*x^2 + 84*x^3 + 380*x^4 + 1540*x^5 +... =
1/[(1-4*x)*(1-16*x^2)^(1/4)*(1-64*x^3)^(1/16)*(1-256*x^4)^(1/64)*...]
		

Crossrefs

Programs

  • PARI
    a(n)=polcoeff(prod(k=1,n,1/(1-4^k*x^k+x*O(x^n))^(4/4^k)),n)

A110155 G.f.: A(x) = Product_{n>=1} 1/(1 - 5^n*x^n)^(5/5^n).

Original entry on oeis.org

1, 5, 30, 155, 855, 4305, 23255, 116705, 614655, 3108355, 16168430, 81136755, 422279580, 2116775030, 10893334980, 54857686305, 281413208380, 1410806289330, 7237582729155, 36262232611605, 185184341144805
Offset: 0

Views

Author

Paul D. Hanna, Jul 14 2005

Keywords

Examples

			A(x) = 1 + 5*x + 30*x^2 + 155*x^3 + 855*x^4 + 4305*x^5 +... =
1/[(1-5*x)*(1-25*x^2)^(1/5)*(1-125*x^3)^(1/25)*(1-625*x^4)^(1/125)*...]
		

Crossrefs

Programs

  • PARI
    a(n)=polcoeff(prod(k=1,n,1/(1-5^k*x^k+x*O(x^n))^(5/5^k)),n)

A110156 G.f.: A(x) = Product_{n>=1} 1/(1 - 4^n*x^n)^(2/4^n); self-convolution equals A110154.

Original entry on oeis.org

1, 2, 8, 26, 106, 350, 1512, 5110, 21476, 77886, 319148, 1141038, 4910266, 17499058, 72541048, 272237050, 1121013506, 4112829790, 17377874692, 63697436318, 265450712278, 1003409368250, 4102752994248, 15321419162722, 64725434306768
Offset: 0

Views

Author

Paul D. Hanna, Jul 14 2005

Keywords

Examples

			A(x) = 1 + 2*x + 8*x^2 + 26*x^3 + 106*x^4 + 350*x^5 +... =
1/[(1-4*x)^(2/4)*(1-16*x^2)^(2/16)*(1-64*x^3)^(2/64)*...].
		

Crossrefs

Programs

  • PARI
    a(n)=polcoeff(prod(k=1,n,1/(1-4^k*x^k+x*O(x^n))^(2/4^k)),n)
Showing 1-4 of 4 results.