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 12 results. Next

A130900 Number of partitions of n into {number of partitions of n into "number of partitions of n into 'number of partitions of n into partition numbers' numbers" numbers} numbers.

Original entry on oeis.org

1, 2, 3, 5, 6, 10, 12, 17, 22, 29, 36, 48, 58, 73, 91, 111, 134, 165, 197, 236, 283, 335, 395, 468, 547, 639, 747, 866, 1001, 1160, 1334, 1530, 1757, 2007, 2286, 2606, 2958, 3349, 3793, 4281, 4821, 5430, 6097, 6833, 7657, 8559, 9549, 10652, 11858, 13178
Offset: 1

Views

Author

Graeme McRae, Jun 07 2007

Keywords

Comments

The "partition transformation" of sequence A can be defined as the number of partitions of n into elements of sequence A. This sequence (A130900) is the partition transformation composed with itself five times on the positive integers.

Examples

			a(6) = 10 because there are 10 partitions of 6 whose parts are 1,2,3,4,6 which are terms of sequence A130899, which is the number of partitions of n into numbers of partitions of n into numbers of partitions of n into partition numbers.
		

Crossrefs

Cf. A000027, A000041, A007279, A130898, A130899, A130900 which are m-fold self-compositions of the "partition transformation" on the counting numbers, m=0, 1, 2, 4, 5.

Programs

  • Maple
    pp:= proc(p) local b;
           b:= proc(n, i)
                 if n<0 then 0
               elif n=0 then 1
               elif i<1 then 0
               else b(n,i):= b(n,i-1) +b(n-p(i), i)
                 fi
               end;
           n-> b(n, n)
         end:
    a:= (pp@@5)(n->n):
    seq(a(n), n=1..100);  # Alois P. Heinz, Sep 13 2011
  • Mathematica
    pp[p_] := Module[{b}, b[n_, i_] := Which[n < 0, 0, n == 0, 1, i < 1, 0, True, b[n, i] = b[n, i - 1] + b[n - p[i], i]]; b[#, #]&]; a = Nest[pp, Identity, 5]; Table[a[n], {n, 1, 100}] (* Jean-François Alcover, Oct 26 2015, after Alois P. Heinz *)

A229362 a(n) = n for n = 1, 2, 3; for n > 3: a(n) = number of partitions of n into preceding terms.

Original entry on oeis.org

1, 2, 3, 4, 6, 10, 12, 17, 21, 29, 34, 47, 55, 71, 84, 107, 124, 156, 180, 221, 256, 310, 355, 428, 488, 578, 660, 775, 879, 1027, 1160, 1342, 1516, 1743, 1958, 2243, 2513, 2858, 3198, 3621, 4037, 4556, 5065, 5689, 6316, 7069, 7824, 8733, 9644, 10726, 11827
Offset: 1

Views

Author

Reinhard Zumkeller, Sep 21 2013

Keywords

Examples

			a(4) = #{3+1, 2+2, 2+1+1, 1+1+1+1} = 4 < A000041(4) = 5;
a(5) = #{4+1, 3+2, 3+1+1, 2+2+1, 2+1+1+1, 5x1} = 6 < A000041(5) = 7;
a(6) = #{6, 4+2, 4+1+1, 3+3, 3+2+1, 3+1+1+1, 2+2+2, 2+2+1+1, 2+4x1, 6x1} = 10 < A000041(6) = 11;
a(7) = #{6+1, 4+3, 4+2+1, 4+1+1+1, 3+3+1, 3+2+2, 3+2+1+1, 3+4x1, 2+2+2+1, 2+2+1+1+1, 2+5x1, 7x1} = 12 < A000041(7) = 15.
		

Crossrefs

Programs

  • Haskell
    a229362 n = a229362_list !! (n-1)
    a229362_list = 1 : 2 : 3 : f 4 [1,2,3] where
       f x ys = y : f (x + 1) (ys ++ [y]) where y = p ys x
       p _          0 = 1
       p []         _ = 0
       p ks'@(k:ks) m = if m < k then 0 else p ks' (m - k) + p ks m
  • Mathematica
    a[n_] := a[n] = If[n<4, n, IntegerPartitions[n, All, Array[a, n-1]] // Length];
    Table[Print[n, " ", a[n]]; a[n], {n, 1, 100}] (* Jean-François Alcover, Mar 12 2019 *)

A280253 Expansion of Product_{k>=1} (1 + x^p(k)), where p(k) is the number of partitions of k (A000041).

Original entry on oeis.org

1, 1, 1, 2, 1, 2, 2, 2, 3, 2, 3, 3, 3, 3, 3, 4, 4, 4, 5, 4, 4, 5, 5, 6, 5, 6, 6, 6, 6, 6, 7, 6, 7, 8, 7, 7, 8, 8, 9, 8, 9, 9, 9, 10, 9, 11, 9, 10, 12, 10, 11, 11, 11, 12, 11, 12, 13, 13, 14, 14, 14, 13, 13, 15, 15, 14, 15, 15, 15, 15, 15, 16, 16, 16, 17, 17, 15, 17, 19, 19, 20, 19, 20, 20, 19, 21, 20, 20, 21, 21, 22
Offset: 0

Views

Author

Ilya Gutkovskiy, Dec 30 2016

Keywords

Comments

Number of partitions of n into distinct partition numbers.

Examples

			a(8) = 3 because we have [7, 1], [5, 3] and [5, 2, 1].
		

Crossrefs

Programs

  • Mathematica
    nmax = 90; CoefficientList[Series[Product[(1 + x^PartitionsP[k]), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

G.f.: Product_{k>=1} (1 + x^p(k)).

A293806 a(0) = a(1) = 1; a(n) = [x^n] Product_{k=1..n-1} 1/(1 - x^a(k)).

Original entry on oeis.org

1, 1, 1, 4, 6, 8, 11, 14, 19, 24, 30, 37, 47, 57, 70, 84, 102, 121, 144, 170, 202, 235, 275, 319, 372, 429, 495, 567, 652, 742, 848, 963, 1095, 1237, 1399, 1574, 1775, 1990, 2235, 2499, 2795, 3114, 3473, 3859, 4292, 4755, 5271, 5827, 6444, 7107, 7840, 8625, 9493, 10422, 11444, 12541
Offset: 0

Views

Author

Ilya Gutkovskiy, Oct 16 2017

Keywords

Comments

a(n) = number of partitions of n into preceding terms starting from a(1), a(2), a(3), ... (for n > 1).

Examples

			a(4) = 6 because we have [4], [1a, 1a, 1a, 1a], [1a, 1a, 1a, 1b], [1a, 1a, 1b, 1b],  [1a, 1b, 1b, 1b] and [1b, 1b, 1b, 1b].
G.f. = -x - 2*x^2 + 1/((1 - x)*(1 - x)*(1 - x^4)*(1 - x^6)*(1 - x^8)*(1 - x^11)*(1 - x^14)*(1 - x^19)*...) = 1 + x + x^2 + 4*x^3 + 6*x^4 + 8*x^5 + 11*x^6 + 14*x^7 + 19*x^8 + ...
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
          b(n, i-1)+`if`(a(i)>n, 0, b(n-a(i), i))))
        end:
    a:= n-> `if`(n<2, 1, b(n, n-1)):
    seq(a(n), n=0..60);  # Alois P. Heinz, Oct 16 2017
  • Mathematica
    a[n_] := a[n] = SeriesCoefficient[Product[1/(1 - x^a[k]), {k, 1, n - 1}], {x, 0, n}]; a[0] = a[1] = 1; Table[a[n], {n, 0, 55}]

Formula

G.f. A(x) = Sum_{n>=0} a(n)*x^n satisfies A(x) = -x - 2*x^2 + Product_{n>=1} 1/(1 - x^a(n)).

A130898 Number of partitions of n into "number of partitions of n into partition numbers" numbers.

Original entry on oeis.org

1, 2, 3, 5, 6, 10, 12, 18, 22, 30, 37, 50, 59, 78, 93, 118, 140, 176, 206, 255, 297, 362, 421, 507, 585, 699, 803, 949, 1088, 1276, 1455, 1696, 1927, 2230, 2527, 2909, 3284, 3761, 4233, 4825, 5416, 6146, 6879, 7778, 8682, 9778, 10892, 12226, 13582, 15200
Offset: 1

Views

Author

Graeme McRae, Jun 07 2007

Keywords

Comments

The "partition transformation" of sequence A can be defined as the number of partitions of n into elements of sequence A. This is the partition transformation composed with itself three times on the positive integers.
a(6) = 10 because there are 10 partitions of 6 whose parts are 1,2,3,4,6 which are terms of sequence A007279, which is the number of partitions of n into partition numbers.

Examples

			a(6) = 12 because there are 12 partitions of 6 whose parts are 1,2,3,4,6 which are terms of sequence A007279, which is the number of partitions of n into partition numbers.
		

Crossrefs

Cf. A000027, A000041, A007279, A130899, A130900 which are m-fold self-compositions of the "partition transformation" on the counting numbers, for m=0, 1, 2, 4, 5.

Programs

  • Maple
    pp:= proc(p) local b;
           b:= proc(n, i)
                 if n<0 then 0
               elif n=0 then 1
               elif i<1 then 0
               else b(n,i):= b(n,i-1) +b(n-p(i), i)
                 fi
               end;
           n-> b(n, n)
         end:
    a:= (pp@@3)(n->n):
    seq(a(n), n=1..100); # Alois P. Heinz, Sep 13 2011
  • Mathematica
    pp[p_] := Module[{b}, b[n_, i_] := Which[n<0, 0, n==0, 1, i<1, 0, True, b[n, i] = b[n, i-1] + b[n-p[i], i]]; b[#, #]&]; a = Nest[pp, Identity, 3]; Table[a[n], {n, 1, 100}] (* Jean-François Alcover, Oct 26 2015, after Alois P. Heinz *)

A130899 Number of partitions of n into "number of partitions of n into 'number of partitions of n into partition numbers' numbers" numbers.

Original entry on oeis.org

1, 2, 3, 4, 6, 9, 11, 15, 19, 25, 31, 41, 49, 61, 75, 91, 109, 134, 156, 188, 221, 262, 305, 361, 416, 485, 560, 648, 740, 858, 972, 1115, 1266, 1441, 1627, 1851, 2078, 2348, 2634, 2965, 3309, 3721, 4138, 4625, 5143, 5728, 6344, 7059, 7792, 8637, 9525, 10529
Offset: 1

Views

Author

Graeme McRae, Jun 07 2007

Keywords

Comments

The "partition transformation" of sequence A can be defined as the number of partitions of n into elements of sequence A. This sequence (A130899) is the partition transformation composed with itself four times on the positive integers.

Examples

			a(6) = 9 because there are 9 partitions of 6 whose parts are 1,2,3,5,6 which are terms of sequence A130898, which is the number of partitions of n into numbers of partitions of n into partition numbers.
		

Crossrefs

Cf. A000027, A000041, A007279, A130898, A130900 which are m-fold self-compositions of the "partition transformation" on the counting numbers, for m=0, 1, 2, 4, 5.

Programs

  • Maple
    pp:= proc(p) local b;
           b:= proc(n, i)
                 if n<0 then 0
               elif n=0 then 1
               elif i<1 then 0
               else b(n,i):= b(n,i-1) +b(n-p(i), i)
                 fi
               end;
           n-> b(n, n)
         end:
    a:= (pp@@4)(n->n):
    seq(a(n), n=1..100); # Alois P. Heinz, Sep 13 2011
  • Mathematica
    pp[p_] := Module[{b}, b[n_, i_] := Which[n < 0, 0, n == 0, 1, i < 1, 0, True, b[n, i] = b[n, i-1] + b[n-p[i], i]]; b[#, #]&]; a = Nest[pp, Identity, 4]; Table[a[n], {n, 1, 100}] (* Jean-François Alcover, Oct 26 2015, after Alois P. Heinz *)

A068006 Number of partitions of n into distinct partition numbers.

Original entry on oeis.org

1, 2, 5, 9, 17, 28, 47, 72, 112, 164, 242, 342, 486, 668, 920, 1237, 1663, 2193, 2891, 3750, 4861, 6218, 7944, 10037, 12664, 15827, 19749, 24444, 30204, 37057, 45391, 55250, 67141, 81140, 97895, 117529, 140873, 168105, 200285, 237672, 281604
Offset: 0

Views

Author

Robert G. Wilson v, Feb 11 2002

Keywords

Crossrefs

Programs

  • Mathematica
    CoefficientList[ Series[1/Product[1 - x^PartitionsQ[i], {i, 1, 50}], {x, 0, 50}], x]

Formula

G.f.: Product_{n>=1} (1/(1-x^A000009(n))).

Extensions

Offset corrected by Sean A. Irvine, Jan 18 2024

A086209 Number of partitions of n-th partition number into partition numbers.

Original entry on oeis.org

1, 1, 2, 3, 6, 11, 29, 66, 216, 656, 2595, 9744, 49895, 232379, 1409681, 8499639, 62575472, 457432705, 4149365733, 37128654099, 403871166718, 4462555420780, 57791900756532, 769856248243565, 12070457173762581, 193254691673461508, 3581624759657803466
Offset: 0

Views

Author

Reinhard Zumkeller, Aug 27 2003

Keywords

Comments

a(n) = A007279(A000041(n)).

Extensions

a(0), a(17)-a(26) from Alois P. Heinz, Jul 04 2017

A062464 Nearest integer to log(n)^sqrt(n).

Original entry on oeis.org

0, 1, 1, 2, 3, 4, 6, 8, 11, 14, 18, 23, 30, 38, 47, 59, 73, 90, 111, 135, 164, 199, 240, 288, 346, 413, 491, 583, 691, 816, 962, 1131, 1327, 1554, 1816, 2118, 2465, 2865, 3323, 3849, 4451, 5139, 5925, 6821, 7842, 9003, 10324, 11823, 13523, 15449
Offset: 1

Views

Author

Olivier Gérard, Jun 23 2001

Keywords

Crossrefs

Cf. A062463, close to A007279 and A034891.

Programs

  • Mathematica
    Table[Round[Log[n]^Sqrt[n]],{n,50}] (* Harvey P. Dale, Dec 31 2021 *)

Extensions

Previous Mathematica program replaced by Harvey P. Dale, Dec 31 2021

A291693 Expansion of Product_{k>=1} (1 + x^q(k)), where q(k) = [x^k] Product_{k>=1} (1 + x^k).

Original entry on oeis.org

1, 2, 3, 5, 6, 8, 11, 13, 16, 19, 22, 26, 30, 34, 38, 44, 49, 54, 62, 67, 74, 83, 89, 98, 107, 115, 124, 134, 145, 155, 168, 178, 189, 206, 217, 231, 247, 259, 277, 294, 310, 327, 345, 365, 382, 404, 424, 444, 470, 489, 513, 539, 561, 588, 613, 641, 670, 699, 729, 756, 791, 824
Offset: 0

Views

Author

Ilya Gutkovskiy, Aug 30 2017

Keywords

Comments

Number of partitions of n into distinct terms of A000009, where 2 different parts of 1 and 2 different parts of 2 are available (1a, 1b, 2a, 2b, 3a, 4a, 5a, 6a, ...).

Examples

			a(3) = 5 because we have [3a], [2a, 1a], [2a, 1b], [2b, 1a] and [2b, 1b].
		

Crossrefs

Programs

  • Maple
    N:= 20: # to get a(0) .. a(A000009(N))
    P:= mul(1+x^k,k=1..N):
    R:= mul(1+x^coeff(P,x,n)),n=1..N):
    seq(coeff(R,x,n),n=0..coeff(P,x,N)); # Robert Israel, Sep 01 2017
  • Mathematica
    nmax = 61; CoefficientList[Series[Product[1 + x^PartitionsQ[k], {k, 1, nmax}], {x, 0, nmax}], x]

Formula

G.f.: Product_{k>=1} (1 + x^A000009(k)).
Showing 1-10 of 12 results. Next