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.

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A306033 Number of length-n restricted growth strings (RGS) with growth <= nine and first element in [9].

Original entry on oeis.org

1, 9, 126, 2229, 46791, 1126032, 30377223, 904211997, 29347973748, 1029154793775, 38706399597879, 1551902279238186, 65998768155695109, 2964410257125490269, 140111251278756345054, 6946234487211269640633, 360202406323880296650987, 19488725004898446787394016
Offset: 0

Views

Author

Alois P. Heinz, Jun 17 2018

Keywords

Crossrefs

Column k=9 of A306024.
Cf. A305969.

Programs

  • Maple
    b:= proc(n, m) option remember; `if`(n=0, 1,
          add(b(n-1, max(m, j)), j=1..m+9))
        end:
    a:= n-> b(n, 0):
    seq(a(n), n=0..25);
    # second Maple program:
    a:= n-> n!*coeff(series(exp(add((exp(j*x)-1)/j, j=1..9)), x, n+1), x, n):
    seq(a(n), n=0..25);

Formula

E.g.f.: exp(Sum_{j=1..9} (exp(j*x)-1)/j).

A306034 Number of length-n restricted growth strings (RGS) with growth <= ten and first element in [10].

Original entry on oeis.org

1, 10, 155, 3035, 70500, 1877083, 56019305, 1844512570, 66219313755, 2568394851483, 106837050484924, 4737487302902715, 222819378516865825, 11068264704881204698, 578536038611685742843, 31718762374848254987147, 1818933941414434687198820
Offset: 0

Views

Author

Alois P. Heinz, Jun 17 2018

Keywords

Crossrefs

Column k=10 of A306024.
Cf. A305970.

Programs

  • Maple
    b:= proc(n, m) option remember; `if`(n=0, 1,
          add(b(n-1, max(m, j)), j=1..m+10))
        end:
    a:= n-> b(n, 0):
    seq(a(n), n=0..25);
    # second Maple program:
    a:= n-> n!*coeff(series(exp(add((exp(j*x)-1)/j, j=1..10)), x, n+1), x, n):
    seq(a(n), n=0..25);

Formula

E.g.f.: exp(Sum_{j=1..10} (exp(j*x)-1)/j).

A355427 Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. 1/(1 - Sum_{j=1..k} (exp(j*x) - 1)/j).

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 2, 3, 0, 1, 3, 11, 13, 0, 1, 4, 24, 89, 75, 0, 1, 5, 42, 284, 959, 541, 0, 1, 6, 65, 654, 4476, 12917, 4683, 0, 1, 7, 93, 1255, 13564, 88178, 208781, 47293, 0, 1, 8, 126, 2143, 32275, 351634, 2084564, 3937019, 545835, 0
Offset: 0

Views

Author

Seiichi Manyama, Jul 01 2022

Keywords

Examples

			Square array begins:
  1,   1,     1,     1,      1,       1, ...
  0,   1,     2,     3,      4,       5, ...
  0,   3,    11,    24,     42,      65, ...
  0,  13,    89,   284,    654,    1255, ...
  0,  75,   959,  4476,  13564,   32275, ...
  0, 541, 12917, 88178, 351634, 1037479, ...
		

Crossrefs

Columns k=0..3 give A000007, A000670, A355425, A355426.
Main diagonal gives A355428.

Formula

T(0,k) = 1 and T(n,k) = Sum_{i=1..n} (Sum_{j=1..k} j^(i-1)) * binomial(n,i) * T(n-i,k) for n > 0.

A355423 Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. exp(Sum_{j=1..k} (exp(j*x) - 1)).

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 3, 2, 0, 1, 6, 14, 5, 0, 1, 10, 50, 81, 15, 0, 1, 15, 130, 504, 551, 52, 0, 1, 21, 280, 2000, 5870, 4266, 203, 0, 1, 28, 532, 6075, 35054, 76872, 36803, 877, 0, 1, 36, 924, 15435, 148429, 684000, 1111646, 348543, 4140, 0
Offset: 0

Views

Author

Seiichi Manyama, Jul 01 2022

Keywords

Examples

			Square array begins:
  1,  1,    1,     1,      1,       1, ...
  0,  1,    3,     6,     10,      15, ...
  0,  2,   14,    50,    130,     280, ...
  0,  5,   81,   504,   2000,    6075, ...
  0, 15,  551,  5870,  35054,  148429, ...
  0, 52, 4266, 76872, 684000, 4004100, ...
		

Crossrefs

Columns k=0-4 give: A000007, A000110, A355291, A355421, A355422.
Main diagonal gives A320288.

Formula

T(0,k) = 1 and T(n,k) = Sum_{i=1..n} (Sum_{j=1..k} j^i) * binomial(n-1,i-1) * T(n-i,k) for n > 0.
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