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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A336902 Sum of the smallest parts of all compositions of n into distinct parts.

Original entry on oeis.org

0, 1, 2, 5, 6, 11, 18, 25, 32, 53, 84, 107, 156, 205, 302, 497, 618, 863, 1206, 1597, 2228, 3569, 4440, 6191, 8256, 11329, 14642, 20477, 30390, 38555, 52578, 69625, 92696, 122141, 160500, 211955, 310476, 386941, 521102, 678617, 901386, 1155383, 1529742, 1940749
Offset: 0

Views

Author

Alois P. Heinz, Aug 07 2020

Keywords

Examples

			a(6) = 18 = 1 + 1 + 1 + 1 + 1 + 1 + 2 + 2 + 1 + 1 + 6: (1)23, (1)32, 2(1)3, 23(1), 3(1)2, 32(1), (2)4, 4(2), (1)5, 5(1), (6).
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i, p) option remember; `if`(i*(i+1)/2 b(n$2, 1):
    seq(a(n), n=0..50);
  • Mathematica
    b[n_, i_, p_] := b[n, i, p] = If[i(i+1)/2 < n || i < 1, 0,
         If[i == n, i*p!, b[n-i, Min[n-i, i-1], p+1]] + b[n, i-1, p]];
    a[n_] := b[n, n, 1];
    Table[a[n], {n, 0, 50}] (* Jean-François Alcover, Jul 12 2021, after Alois P. Heinz *)

Formula

a(n) == n (mod 2).

A336903 Sum of the largest parts of all compositions of n into distinct parts.

Original entry on oeis.org

0, 1, 2, 7, 10, 19, 42, 61, 98, 151, 304, 403, 654, 925, 1400, 2431, 3328, 4903, 7056, 10117, 13952, 23419, 30406, 44683, 61308, 87289, 116822, 164359, 247774, 327715, 457542, 624445, 855062, 1148023, 1559188, 2058643, 3043506, 3906637, 5375732, 7111975, 9679852
Offset: 0

Views

Author

Alois P. Heinz, Aug 07 2020

Keywords

Examples

			a(6) = 42 = 3 + 3 + 3 + 3 + 3 + 3 + 4 + 4 + 5 + 5 + 6: 12(3), 1(3)2, 21(3), 2(3)1, (3)12, (3)21, 2(4), (4)2, 1(5), (5)1, (6).
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i, p) option remember; `if`(i*(i+1)/2 `if`(n=0, 0, b(n$2, 0)):
    seq(a(n), n=0..50);
  • Mathematica
    b[n_, i_, p_] := b[n, i, p] = If[i(i + 1)/2 < n, 0,
         If[n == 0, p!, b[n - i, Min[n - i, i - 1], p + 1]*
         If[p == 0, i, 1] + b[n, i - 1, p]]];
    a[n_] := If[n == 0, 0, b[n, n, 0]];
    Table[a[n], {n, 0, 50}] (* Jean-François Alcover, Jul 12 2021, after Alois P. Heinz *)

Formula

a(n) == n (mod 2).

A097147 Total sum of minimum block sizes in all partitions of n-set.

Original entry on oeis.org

1, 3, 7, 21, 66, 258, 1079, 4987, 25195, 136723, 789438, 4863268, 31693715, 217331845, 1564583770, 11795630861, 92833623206, 760811482322, 6479991883525, 57256139503047, 523919025038279, 4956976879724565, 48424420955966635, 487810283307069696
Offset: 1

Views

Author

Vladeta Jovovic, Jul 27 2004

Keywords

Crossrefs

Programs

  • Maple
    g:= proc(n, i, p) option remember; `if`(n=0, (i+1)*p!,
          `if`(i<1, 0, add(g(n-i*j, i-1, p+j*i)/j!/i!^j, j=0..n/i)))
        end:
    a:= n-> g(n$2, 0):
    seq(a(n), n=1..30);  # Alois P. Heinz, Mar 06 2015
  • Mathematica
    Drop[Apply[Plus,Table[nn=25;Range[0,nn]!CoefficientList[Series[Exp[Sum[ x^i/i!,{i,n,nn}]]-1,{x,0,nn}],x],{n,1,nn}]],1]  (* Geoffrey Critzer, Jan 10 2013 *)
    g[n_, i_, p_] := g[n, i, p] = If[n == 0, (i+1)*p!, If[i<1, 0,
         Sum[g[n-i*j, i-1, p+j*i]/j!/i!^j, {j, 0, n/i}]]];
    a[n_] := g[n, n, 0];
    Array[a, 30] (* Jean-François Alcover, Aug 24 2021, after Alois P. Heinz *)

Formula

E.g.f.: Sum_{k>0} (-1+exp(Sum_{j>=k} x^j/j!)).

Extensions

More terms from Max Alekseyev, Apr 29 2010

A097148 Total sum of maximum block sizes in all partitions of n-set.

Original entry on oeis.org

1, 3, 10, 35, 136, 577, 2682, 13435, 72310, 414761, 2524666, 16239115, 109976478, 781672543, 5814797281, 45155050875, 365223239372, 3070422740989, 26780417126048, 241927307839731, 2260138776632752, 21805163768404127, 216970086170175575, 2224040977932468379
Offset: 1

Views

Author

Vladeta Jovovic, Jul 27 2004

Keywords

Comments

Let M be the infinite lower triangular matrix given by A080510 and v the column vector [1,2,3,...] then M*v=A097148 (this sequence, as column vector). - Gary W. Adamson, Feb 24 2011

Crossrefs

Programs

  • Maple
    b:= proc(n, m) option remember; `if`(n=0, m, add(
          b(n-j, max(j, m))*binomial(n-1, j-1), j=1..n))
        end:
    a:= n-> b(n, 0):
    seq(a(n), n=1..24);  # Alois P. Heinz, Mar 02 2020, revised May 08 2024
  • Mathematica
    Drop[ Range[0, 22]! CoefficientList[ Series[ Sum[E^(E^x - 1) - E^Sum[x^j/j!, {j, 1, k}], {k, 0, 22}], {x, 0, 22}], x], 1] (* Robert G. Wilson v, Aug 05 2004 *)

Formula

E.g.f.: Sum_{k>=0} (exp(exp(x)-1)-exp(Sum_{j=1..k} x^j/j!)).

Extensions

More terms from Robert G. Wilson v, Aug 05 2004

A182707 Sum of the parts of all partitions of n-1 plus the sum of the emergent parts of the partitions of n.

Original entry on oeis.org

0, 1, 4, 11, 23, 46, 80, 138, 221, 351, 529, 801, 1161, 1685, 2380, 3355, 4624, 6375, 8623, 11658, 15538, 20664, 27163, 35660, 46330, 60082, 77288, 99197, 126418, 160802, 203246, 256381, 321700, 402781, 501962, 624332, 773235, 955776, 1177076, 1446762, 1772308
Offset: 1

Views

Author

Omar E. Pol, Nov 28 2010

Keywords

Comments

For more information about the emergent parts of the partitions of n see A182699 and A182709.

Examples

			For n = 6 the partitions of 6-1=5 are (5);(3+2);(4+1);(2+2+1);(3+1+1);(2+1+1+1);(1+1+1+1+1) and the sum of the parts give 35, the same as 5*7. By other hand the emergent parts of the partitions of 6 are (2+2);(4);(3) and the sum give 11, so a(6) = 35+11 = 46.
		

Crossrefs

Formula

a(n) = A066186(n) - A046746(n) = A066186(n-1) + A182709(n).
a(n) ~ exp(Pi*sqrt(2*n/3)) / (4*sqrt(3)) * (1 - (sqrt(3/2)/Pi + Pi/(24*sqrt(6)))/sqrt(n)). - Vaclav Kotesovec, Jan 03 2019, extended Jul 06 2019

A097940 Sum of smallest parts (counted with multiplicity) of all compositions of n.

Original entry on oeis.org

1, 4, 8, 20, 37, 86, 173, 372, 788, 1680, 3550, 7554, 15994, 33820, 71374, 150376, 316151, 663474, 1389760, 2906116, 6066899, 12645608, 26318870, 54700044, 113536171, 235363832, 487342781, 1007969620, 2082597193, 4298660754, 8864505305, 18263797648, 37597869188
Offset: 1

Views

Author

Vladeta Jovovic, Sep 05 2004

Keywords

Crossrefs

Programs

  • Mathematica
    Drop[ CoefficientList[ Series[(1 - x)^2*Sum[k*x^k/(1 - x - x^k)^2, {k, 50}], {x, 0, 30}], x], 1] (* Robert G. Wilson v, Sep 08 2004 *)

Formula

G.f.: (1-x)^2 * Sum_{k>=1} k*x^k/(1-x-x^k)^2.
a(n) ~ n * 2^(n-3). - Vaclav Kotesovec, Sep 05 2014
a(n) = Sum_{k=1..n} A308630(n,k). - R. J. Mathar, Jun 12 2019

Extensions

More terms from Robert G. Wilson v, Sep 08 2004

A196025 Total sum of parts greater than 1 in all the partitions of n except one copy of the smallest part greater than 1 of every partition.

Original entry on oeis.org

0, 0, 0, 2, 5, 16, 30, 63, 108, 189, 298, 483, 720, 1092, 1582, 2297, 3225, 4551, 6244, 8592, 11590, 15622, 20741, 27536, 36066, 47198, 61150, 79077, 101391, 129808, 164934, 209213, 263745, 331807, 415229, 518656, 644719, 799926, 988432, 1218979
Offset: 1

Views

Author

Omar E. Pol, Oct 27 2011

Keywords

Comments

Also partial sums of A182709. Total sum of emergent parts in all partitions of all numbers <= n.
Also total sum of parts of all regions of n that do not contain 1 as a part (Cf. A083751, A187219). - Omar E. Pol, Mar 04 2012

Crossrefs

Formula

a(n) = A066186(n) - A196039(n).
a(n) ~ exp(Pi*sqrt(2*n/3)) / (4*sqrt(3)). - Vaclav Kotesovec, Jul 06 2019

A196930 Triangle read by rows in which row n lists in nondecreasing order the smallest part of every partition of n that do not contain 1 as a part, with a(1) = 1.

Original entry on oeis.org

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

Views

Author

Omar E. Pol, Oct 21 2011

Keywords

Comments

For n >= 2, row n lists the parts of the head of the last section of the set of partitions of n, except the emergent parts.
Also 1 together with the integers > 1 of A196931.

Examples

			Written as a triangle:
1,
2,
3,
2,4,
2,5,
2,2,3,6
2,2,3,7,
2,2,2,2,3,4,8,
2,2,2,2,3,3,4,9,
2,2,2,2,2,2,2,3,3,4,5,10,
2,2,2,2,2,2,2,2,3,3,3,4,5,11,
2,2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,4,4,5,6,12,
2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,4,4,5,6,13,
...
Row n has length A002865(n), n >= 2. The sum of row n is A182708(n), n >= 2. The number of 2's in row n is A002865(n-2), n >= 4. Right border of triangle gives A000027.
		

Crossrefs

Where records occur give A000041.

Programs

  • Maple
    p:= (f, g)-> zip((x, y)->x+y, f, g, 0):
    b:= proc(n, i) option remember; local g, j, r;
          if n=0 then [1] elif i<2 then [0]
        else r:= b(n, i-1);
             for j to n/i do g:= b(n-i*j, i-1);
               r:= p(p(r, [0$i, g[1]]), subsop(1=0, g));
             od; r
          fi
        end:
    T:= proc(n) local l; l:= b(n$2);
          `if`(n=1, 1, seq(i$l[i+1], i=2..nops(l)-1))
        end:
    seq(T(n), n=1..16);  # Alois P. Heinz, May 30 2013
  • Mathematica
    p[f_, g_] := Plus @@ PadRight[{f, g}]; b[n_, i_] := b[n, i] = Module[{ g, j, r}, Which[n == 0, {1}, i<2, {0}, True, r = b[n, i-1]; For[j = 1, j <= n/i, j++, g = b[n-i*j, i-1]; r = p[p[r, Append[Array[0&, i], g // First]], ReplacePart[g, 1 -> 0]]]; r]]; T[n_] := Module[{l}, l = b[n, n]; If[n == 1, {1}, Table[Array[i&, l[[i+1]]], {i, 2, Length[l]-1}] // Flatten]]; Table[T[n], {n, 1, 16}] // Flatten (* Jean-François Alcover, Jan 30 2014, after Alois P. Heinz *)

A206283 Triangle read by rows: T(n,k) = sum of the k-th parts of all partitions of n with their parts written in nondecreasing order.

Original entry on oeis.org

1, 3, 1, 5, 3, 1, 9, 7, 3, 1, 12, 12, 7, 3, 1, 20, 21, 14, 7, 3, 1, 25, 31, 24, 14, 7, 3, 1, 38, 47, 40, 26, 14, 7, 3, 1, 49, 66, 61, 43, 26, 14, 7, 3, 1, 69, 93, 92, 70, 45, 26, 14, 7, 3, 1, 87, 124, 130, 106, 73, 45, 26, 14, 7, 3, 1
Offset: 1

Views

Author

Omar E. Pol, Feb 13 2012

Keywords

Comments

In row n, the sum of all odd-indexed terms minus the sum of all even-indexed terms is equal to A194714(n).
Reversed rows converge to A014153. - Alois P. Heinz, Feb 13 2012

Examples

			Row 4 is 9, 7, 3, 1 because the five partitions of 4, with their parts written in nondecreasing order, are
.                               4
.                               1, 3
.                               2, 2
.                               1, 1, 2
.                               1, 1, 1, 1
-------------------------------------------
And the sums of the columns are 9, 7, 3, 1.
.
Triangle begins:
   1;
   3,  1;
   5,  3,  1;
   9,  7,  3,  1;
  12, 12,  7,  3,  1;
  20, 21, 14,  7,  3,  1;
  25, 31, 24, 14,  7,  3,  1;
  38, 47, 40, 26, 14,  7,  3,  1;
  49, 66, 61, 43, 26, 14,  7,  3,  1;
  69, 93, 92, 70, 45, 26, 14,  7,  3,  1;
		

Crossrefs

Column 1 is A046746. Row sums give A066186.

Extensions

More terms from Alois P. Heinz, Feb 13 2012

A210953 Triangle read by rows: T(n,k) = sum of all parts in the k-th column of the shell model of partitions considering only the n-th shell and with its parts aligned to the right margin.

Original entry on oeis.org

1, 0, 3, 0, 0, 5, 0, 0, 2, 9, 0, 0, 0, 3, 12, 0, 0, 0, 2, 9, 20, 0, 0, 0, 0, 3, 11, 25, 0, 0, 0, 0, 2, 9, 22, 38, 0, 0, 0, 0, 0, 3, 14, 28, 49, 0, 0, 0, 0, 0, 2, 9, 26, 44, 69, 0, 0, 0, 0, 0, 0, 3, 14, 37, 55, 87, 0, 0, 0, 0, 0, 0, 2, 9, 29, 62, 83, 123
Offset: 1

Views

Author

Omar E. Pol, Apr 22 2012

Keywords

Examples

			For n = 6 and k = 1..6 the 6th shell looks like this:
-------------------------
k: 1,  2,  3,  4,  5,  6
-------------------------
.                      6
.                  3 + 3
.                  4 + 2
.              2 + 2 + 2
.                      1
.                      1
.                      1
.                      1
.                      1
.                      1
.                      1
.
The sums of all parts in columns 1-6 are
.  0,  0,  0,  2,  9, 20, the same as the 6th row of triangle.
Triangle begins:
1;
0, 3;
0, 0, 5;
0, 0, 2, 9;
0, 0, 0, 3, 12;
0, 0, 0, 2,  9, 20;
0, 0, 0, 0,  3, 11, 25;
0, 0, 0, 0,  2,  9, 22, 38;
0, 0, 0, 0,  0,  3, 14, 28, 49;
0, 0, 0, 0,  0,  2,  9, 26, 44, 69;
0, 0, 0, 0,  0,  0,  3, 14, 37, 55, 87;
0, 0, 0, 0,  0,  0,  2,  9, 29, 62, 83, 123;
		

Crossrefs

Row sums give A138879. Column sums converge to A014153. Right border gives A046746, n >= 1.
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