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.

A079265 Number of antisymmetric transitive binary relations on n unlabeled points.

Original entry on oeis.org

1, 2, 7, 32, 192, 1490, 15067, 198296, 3398105, 75734592, 2191591226, 82178300654, 3984499220967, 249298391641352, 20089200308020179, 2081351202770089728
Offset: 0

Views

Author

N. J. A. Sloane, Feb 16 2003

Keywords

Comments

Also, number of unconstrained mixed models with n factors.

References

  • A. Hess and H. Iyer, Enumeration of mixed linear models and SAS macro for computation of confidence intervals for variance components, presented at Applied Statistics in Agriculture Conference at Kansas State University 2001.

Crossrefs

Cf. A000112 (partial orders), A091073 (transitive relations), A001930 (quasi-orders), A085628 (labeled antisymmetric transitive relations).

Extensions

a(10)-a(12) and new description from Goetz Pfeiffer (goetz.pfeiffer(AT)nuigalway.ie), Jan 21 2004
a(13)-a(15) from Brinkmann's and McKay's paper by Vladeta Jovovic, Jan 04 2006

A079263 Number of constrained mixed models with n factors.

Original entry on oeis.org

2, 6, 22, 101, 576, 4162, 38280, 451411, 6847662, 133841440
Offset: 1

Views

Author

N. J. A. Sloane, Feb 16 2003

Keywords

References

  • A. Hess and H. Iyer, Enumeration of mixed linear models and SAS macro for computation of confidence intervals for variance components, presented at Applied Statistics in Agriculture Conference at Kansas State University 2001.

Crossrefs

Extensions

a(10) from Bayon, Lygeros, and Sereni (2005) added by Sean A. Irvine, Aug 05 2025

A353041 G.f. A(x) satisfies: A(x) = 1 + x * A(3*x/(1 + 2*x)) / (1 - x).

Original entry on oeis.org

1, 1, 4, 34, 820, 62140, 14651728, 10547347384, 22950318347248, 150277943334242320, 2955664382713520203072, 174478760893191691170298912, 30905073486465684713191125079360, 16423574117627547687292156418920831936, 26184104208316120602662312616366633316565248
Offset: 0

Views

Author

Ilya Gutkovskiy, Apr 19 2022

Keywords

Crossrefs

Cf. A006898, A047656, A135755 (partial sums), A353042.

Programs

  • Mathematica
    nmax = 14; A[] = 0; Do[A[x] = 1 + x A[3 x/(1 + 2 x)]/(1 - x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
    Table[Sum[Binomial[n - 1, k - 1] 3^(k (k - 1)/2), {k, 0, n}], {n, 0, 14}]

Formula

G.f.: Sum_{k>=0} 3^(k*(k-1)/2) * (x/(1 - x))^k.
a(n) = Sum_{k=0..n} binomial(n-1,k-1) * 3^(k*(k-1)/2).

A353042 G.f. A(x) satisfies: A(x) = 1 + x * A(4*x/(1 + 3*x)) / (1 - x).

Original entry on oeis.org

1, 1, 5, 73, 4301, 1065361, 1079026325, 4404504773593, 72088402948928861, 4722943066827454121761, 1237982543178169058402322725, 1298086594246614900499652230482793, 5444532149619463867564918804810528611821, 91343917667481554378430257939829428893551284401
Offset: 0

Views

Author

Ilya Gutkovskiy, Apr 19 2022

Keywords

Crossrefs

Cf. A006898, A053763, A135756 (partial sums), A353041.

Programs

  • Mathematica
    nmax = 13; A[] = 0; Do[A[x] = 1 + x A[4 x/(1 + 3 x)]/(1 - x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
    Table[Sum[Binomial[n - 1, k - 1] 2^(k (k - 1)), {k, 0, n}], {n, 0, 13}]

Formula

G.f.: Sum_{k>=0} 2^(k*(k-1)) * (x/(1 - x))^k.
a(n) = Sum_{k=0..n} binomial(n-1,k-1) * 2^(k*(k-1)).
Showing 1-4 of 4 results.