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 1-6 of 6 results.

A036072 Erroneous version of A002569.

Original entry on oeis.org

1, 1, 1, 1, 2, 2, 3, 4, 5, 6, 9, 11, 15, 18, 23, 30, 37, 47, 58, 71, 90
Offset: 0

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Keywords

A292994 Number of integers m, 1 <= m <= A002569(n), that are not terms in the triangle T(n,k) of A008284.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 4, 6, 8, 12, 19, 26, 39, 52, 71, 92, 120, 161, 205, 258, 320, 398, 499, 613, 754, 911, 1103, 1340, 1622, 1956, 2338, 2789, 3303, 3938, 4690, 5547, 6551, 7690, 9018, 10584, 12425, 14559, 16989, 19790, 22970, 26615
Offset: 1

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Author

J. Stauduhar, Sep 28 2017

Keywords

Examples

			With n = 10, the maximum value of m is 9 and all values of m from 1 to 9 appear within the first 10 rows of A008284, so a(10) = 0.
With n = 13, the maximum value of m is 18 and all values of m from 1 to 18, except 16 and 17, appear within the first 13 rows of A008284, so a(13) = 2.
		

Crossrefs

Programs

  • Mathematica
    FoldList[{#1, Count[Range@ Max@ #2, k_ /; FreeQ[#1, k]]} & @@ {Append[#1, #2], #2} & @@ {First@ #1, Table[SeriesCoefficient[1/QPochhammer[a q, q], {q, 0, #2}, {a, 0, k}], {k, #2}]} &, {{{1}}, 0}, Range[2, 40]][[All, -1]] (* Michael De Vlieger, Sep 29 2017, after Vladimir Reshetnikov at A008284 *)

A157046 Maximum number of partitions of n into exactly k parts, each <= k. a(n) is maximum in each row of A157044.

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 2, 3, 4, 5, 6, 8, 10, 12, 16, 19, 24, 31, 37, 46, 58, 70, 86, 104, 127, 156, 185, 222, 273, 326, 392, 463, 556, 669, 792, 939, 1109, 1317, 1564, 1838, 2156, 2535, 2986, 3514, 4100, 4777, 5577, 6526, 7621, 8847, 10251, 11869, 13807, 16032, 18529, 21370
Offset: 0

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Author

Wouter Meeussen, Feb 22 2009

Keywords

Comments

Without the constraint on each part being <= k: see A008284 and A002569.

Examples

			For n=9 the counts of partitions for k=1..9 is 0,0,1,4,5,3,2,1,1 so the maximum is 5 (at k=5).
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i, t) option remember; `if`(n=0, 1,
         `if`(i*t max(seq(b(n-i, min(n-i, i-1), i), i=0..n)):
    seq(a(n), n=0..55);  # Alois P. Heinz, May 12 2022
  • Mathematica
    Max @@@ Table[T[n,k,k]-T[n,k-1,k],{n,1,128},{k,n}] (* with T[n,a,b] as defined in A047993 *)

Extensions

a(0)=1 prepended by Alois P. Heinz, May 12 2022

A026819 a(n) = least k such that if 1<=h<=n then T(n,k)>=T(n,h), T given by A008284.

Original entry on oeis.org

1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 16
Offset: 1

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Author

Keywords

Crossrefs

Max{T(n, k)} for 1<=k<=n is A002569.

Programs

  • Mathematica
    f[n_] := Block[{k = 1, mk = mx = 0}, While[k < n + 1, a = Length@ IntegerPartitions[n, {k}]; If[a > mx, mx = a; mk = k]; k++ ]; mk]; Array[f, 85] (* Robert G. Wilson v, Jul 20 2010 *)

Extensions

More terms from Robert G. Wilson v, Jul 20 2010

A325514 Heinz number of row n of the triangle of partition numbers A008284.

Original entry on oeis.org

2, 2, 4, 8, 24, 72, 600, 4200, 101640, 2042040, 107869080, 6435365640, 644779672680, 62219208188280, 14408598135902520, 3195700205016233640, 1246437353286578234760, 527744165981695537415640, 417665868515500206974318760, 314096677106179199154141208440
Offset: 0

Views

Author

Gus Wiseman, May 07 2019

Keywords

Comments

The Heinz number of a positive integer sequence (y_1,...,y_k) is prime(y_1)*...*prime(y_k).

Examples

			The sequence of terms together with their prime indices begins:
             2: {1}
             2: {1}
             4: {1,1}
             8: {1,1,1}
            24: {1,1,1,2}
            72: {1,1,1,2,2}
           600: {1,1,1,2,3,3}
          4200: {1,1,1,2,3,3,4}
        101640: {1,1,1,2,3,4,5,5}
       2042040: {1,1,1,2,3,4,5,6,7}
     107869080: {1,1,1,2,3,5,5,7,8,9}
    6435365640: {1,1,1,2,3,5,5,7,10,10,11}
  644779672680: {1,1,1,2,3,5,6,7,11,12,13,15}
		

Crossrefs

Programs

  • Mathematica
    Times@@@Table[If[n>0&&k==0,1,Prime[Length[IntegerPartitions[n,{k}]]]],{n,0,20},{k,0,n}]

Formula

A001221(a(n)) = A325512(n).
A061395(a(n)) = A002569(n).
A056239(a(n)) = A000041(n).

A046155 k that maximizes partitions of n into exactly k parts.

Original entry on oeis.org

0, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15
Offset: 0

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Author

Keywords

Comments

Essentially the same as A026819. - R. J. Mathar, Oct 18 2008

Crossrefs

A002569(n) = partitions of n into exactly a(n) parts.

Programs

  • Mathematica
    f[n_] := Block[{k = 1, mk = mx = 0}, While[k < n + 1, a = Length@ IntegerPartitions[n, {k}]; If[a > mx, mx = a; mk = k]; k++ ]; mk]; Array[f, 85] (* Robert G. Wilson v, Jul 20 2010 *)
Showing 1-6 of 6 results.