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.

A363507 G.f. satisfies A(x) = exp( Sum_{k>=1} (3 + A(x^k)) * x^k/k ).

Original entry on oeis.org

1, 4, 14, 50, 191, 763, 3180, 13640, 59937, 268304, 1219626, 5614038, 26117296, 122598622, 579977691, 2762264225, 13234003724, 63737225733, 308406648979, 1498558628584, 7309116199687, 35772044402485, 175621484712091, 864670723348447
Offset: 0

Views

Author

Seiichi Manyama, Jun 06 2023

Keywords

Crossrefs

Programs

  • PARI
    seq(n) = my(A=1); for(i=1, n, A=exp(sum(k=1, i, (3+subst(A, x, x^k))*x^k/k)+x*O(x^n))); Vec(A);

Formula

A(x) = Sum_{k>=0} a(k) * x^k = 1/(1-x)^3 * 1/Product_{k>=0} (1-x^(k+1))^a(k).
a(0) = 1; a(n) = (1/n) * Sum_{k=1..n} ( 3 + Sum_{d|k} d * a(d-1) ) * a(n-k).

A363510 G.f. satisfies A(x) = exp( Sum_{k>=1} (-1)^(k+1) * (4 + A(x^k)) * x^k/k ).

Original entry on oeis.org

1, 5, 15, 50, 190, 766, 3231, 14066, 62681, 284591, 1311622, 6120183, 28855529, 137257541, 657894518, 3174411715, 15406640415, 75162477018, 368383443235, 1813007892858, 8956214966017, 44393932344984, 220732441125743, 1100621484436502
Offset: 0

Views

Author

Seiichi Manyama, Jun 06 2023

Keywords

Crossrefs

Programs

  • PARI
    seq(n) = my(A=1); for(i=1, n, A=exp(sum(k=1, i, (-1)^(k+1)*(4+subst(A, x, x^k))*x^k/k)+x*O(x^n))); Vec(A);

Formula

A(x) = Sum_{k>=0} a(k) * x^k = (1+x)^4 * Product_{k>=0} (1+x^(k+1))^a(k).
a(0) = 1; a(n) = (-1/n) * Sum_{k=1..n} ( 4 * (-1)^k + Sum_{d|k} (-1)^(k/d) * d * a(d-1) ) * a(n-k).

A363543 G.f. satisfies A(x) = exp( Sum_{k>=1} (-1)^(k+1) * (3^k + A(x^k)) * x^k/k ).

Original entry on oeis.org

1, 4, 7, 23, 69, 234, 826, 3000, 11168, 42313, 162829, 634052, 2495051, 9903761, 39612048, 159481988, 645833656, 2628829700, 10749777653, 44139474552, 181916530895, 752288709592, 3120574260606, 12981015704961, 54138655342763, 226330448292140
Offset: 0

Views

Author

Seiichi Manyama, Jun 09 2023

Keywords

Crossrefs

Programs

  • PARI
    seq(n) = my(A=1); for(i=1, n, A=exp(sum(k=1, i, (-1)^(k+1)*(3^k+subst(A, x, x^k))*x^k/k)+x*O(x^n))); Vec(A);

Formula

A(x) = Sum_{k>=0} a(k) * x^k = (1+3*x) * Product_{k>=0} (1+x^(k+1))^a(k).
a(0) = 1; a(n) = (-1/n) * Sum_{k=1..n} ( (-3)^k + Sum_{d|k} (-1)^(k/d) * d * a(d-1) ) * a(n-k).

A363566 G.f. satisfies A(x) = exp( Sum_{k>=1} (3 * (-1)^k + A(x^k)) * x^k/k ).

Original entry on oeis.org

1, -2, 2, 0, -2, 0, 5, -3, -9, 11, 16, -34, -27, 102, 30, -296, 56, 807, -548, -2056, 2572, 4770, -9846, -9351, 33822, 11496, -107296, 17853, 316498, -210013, -862785, 1069352, 2122294, -4347217, -4402138, 15657617, 5883290, -51677928, 7420844, 157867636
Offset: 0

Views

Author

Seiichi Manyama, Jun 10 2023

Keywords

Crossrefs

Programs

  • PARI
    seq(n) = my(A=1); for(i=1, n, A=exp(sum(k=1, i, (3*(-1)^k+subst(A, x, x^k))*x^k/k)+x*O(x^n))); Vec(A);

Formula

A(x) = B(x)/(1 + x)^3 where B(x) is the g.f. of A363575.
A(x) = Sum_{k>=0} a(k) * x^k = 1/(1+x)^3 * 1/Product_{k>=0} (1-x^(k+1))^a(k).
a(0) = 1; a(n) = (1/n) * Sum_{k=1..n} ( 3 * (-1)^k + Sum_{d|k} d * a(d-1) ) * a(n-k).
Showing 1-4 of 4 results.