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

A258268 Decimal expansion of a constant related to A206226.

Original entry on oeis.org

9, 1, 5, 3, 3, 7, 0, 1, 9, 2, 4, 5, 4, 1, 2, 2, 4, 6, 1, 9, 4, 8, 5, 3, 0, 2, 9, 2, 4, 0, 1, 3, 5, 4, 5, 4, 0, 0, 7, 3, 3, 2, 7, 2, 0, 4, 1, 2, 1, 8, 4, 8, 8, 4, 9, 6, 8, 9, 2, 6, 3, 2, 0, 1, 4, 7, 6, 1, 3, 8, 3, 7, 6, 6, 8, 9, 5, 7, 3, 1, 6, 2, 3, 9, 1, 5, 1, 9, 0, 2, 5, 5, 8, 7, 9, 5, 1, 9, 2, 8, 4, 5, 3, 8, 9
Offset: 1

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Author

Vaclav Kotesovec, May 25 2015

Keywords

Examples

			9.153370192454122461948530292401354540073...
		

Crossrefs

Programs

  • Mathematica
    r^3/(r-1) /.FindRoot[-PolyLog[2, 1-r] == 3*Log[r]^2/2, {r, E}, WorkingPrecision->120] (* Vaclav Kotesovec, Jun 11 2015 *)

Formula

Equals limit n->infinity A206226(n)^(1/n).
Equals limit n->infinity A206227(n)^(1/n).
Equals limit n->infinity A206240(n)^(1/n).

Extensions

More digits from Vaclav Kotesovec, Jun 10 2015

A238016 Number A(n,k) of partitions of n^k into parts that are at most n; square array A(n,k), n>=0, k>=0, read by antidiagonals.

Original entry on oeis.org

0, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 3, 1, 1, 1, 5, 12, 5, 1, 1, 1, 9, 75, 64, 7, 1, 1, 1, 17, 588, 2280, 377, 11, 1, 1, 1, 33, 5043, 123464, 106852, 2432, 15, 1, 1, 1, 65, 44652, 7566280, 55567352, 6889527, 16475, 22, 1
Offset: 0

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Author

Alois P. Heinz, Feb 17 2014

Keywords

Comments

In general, for k>3, is column k asymptotic to exp(2*n) * n^((k-2)*n-k) / (2*Pi). For k=1 see A000041, for k=2 see A206226 and for k=3 see A238608. - Vaclav Kotesovec, May 25 2015
Conjecture: If f(n) >= O(n^4) then "number of partitions of f(n) into parts that are at most n" is asymptotic to f(n)^(n-1) / (n!*(n-1)!). See also A237998, A238000, A236810 or A258668-A258672. - Vaclav Kotesovec, Jun 07 2015

Examples

			A(3,1) = 3: 3, 21, 111.
A(3,2) = 12: 333, 3222, 3321, 22221, 32211, 33111, 222111, 321111, 2211111, 3111111, 21111111, 111111111.
A(2,3) = 5: 2222, 22211, 221111, 2111111, 11111111.
A(2,4) = 9: 22222222, 222222211, 2222221111, 22222111111, 222211111111, 2221111111111, 22111111111111, 211111111111111, 1111111111111111.
Square array A(n,k) begins:
  0, 1,   1,      1,        1,           1, ...
  1, 1,   1,      1,        1,           1, ...
  1, 2,   3,      5,        9,          17, ...
  1, 3,  12,     75,      588,        5043, ...
  1, 5,  64,   2280,   123464,     7566280, ...
  1, 7, 377, 106852, 55567352, 33432635477, ...
		

Crossrefs

Programs

  • Mathematica
    A[n_, k_] := SeriesCoefficient[Product[1/(1-x^j), {j, 1, n}], {x, 0, n^k}]; A[0, 0] = 0; Table[A[n-k, k], {n, 0, 10}, {k, n, 0, -1}] // Flatten (* Jean-François Alcover, Oct 11 2015 *)

Formula

A(n,k) = [x^(n^k)] Product_{j=1..n} 1/(1-x^j).

A097356 Number of partitions of n into parts not greater than sqrt(n).

Original entry on oeis.org

1, 1, 1, 1, 3, 3, 4, 4, 5, 12, 14, 16, 19, 21, 24, 27, 64, 72, 84, 94, 108, 120, 136, 150, 169, 377, 427, 480, 540, 603, 674, 748, 831, 918, 1014, 1115, 2432, 2702, 3009, 3331, 3692, 4070, 4494, 4935, 5427, 5942, 6510, 7104, 7760, 16475, 18138, 19928, 21873, 23961
Offset: 0

Views

Author

Reinhard Zumkeller, Aug 08 2004

Keywords

Crossrefs

Programs

  • Haskell
    a097356 n = p [1..a000196 n] n where
       p [] _ = 0
       p _  0 = 1
       p ks'@(k:ks) m | m < k     = 0
                      | otherwise = p ks' (m - k) + p ks m
    -- Reinhard Zumkeller, Aug 12 2011
    
  • Maple
    b:= proc(n, i) option remember; `if`(n=0, 1,
          `if`(i<1, 0, b(n, i-1)+b(n-i, min(n-i, i))))
        end:
    a:= n-> b(n, (r-> `if`(r*r>n, r-1, r))(isqrt(n))):
    seq(a(n), n=0..100);  # Alois P. Heinz, Aug 02 2018
  • Mathematica
    Table[Length[IntegerPartitions[n,Floor[Sqrt[n]]]],{n,70}] (* Harvey P. Dale, May 11 2011 *)
    f[n_, 1] := 1; f[1, k_] := 1; f[n_, k_] := f[n, k] = If[k > n, f[n, k - 1], f[n, k - 1] + f[n - k, k]]; Table[ f[n, Floor[Sqrt[n]]], {n, 53}] (* Robert G. Wilson v, Aug 13 2011 *)
  • PARI
    a(n,k=sqrtint(n))=if(min(n,k)<2,1,sum(i=1,min(k,n),a(n-i,i))) \\ Charles R Greathouse IV, Aug 12 2011

Formula

a(n^2) ~ c * d^n / n^2, where d = A258268 = 9.153370192454122461948530292401354... and c = 0.1582087202672504149766310999238... [see A206226, constant c(1)]. The upper bound of a(n) is c * d^sqrt(n) / n, see graph. For the lower bound, the constant c = 0.088154883798697116... (conjectured). - Vaclav Kotesovec, Jan 08 2024

A206240 Number of partitions of n^2-n into parts not greater than n.

Original entry on oeis.org

1, 1, 2, 7, 34, 192, 1206, 8033, 55974, 403016, 2977866, 22464381, 172388026, 1341929845, 10573800028, 84192383755, 676491536028, 5479185281572, 44692412971566, 366844007355202, 3028143252035976, 25123376972033392, 209401287806758273, 1752674793617241002
Offset: 0

Views

Author

Paul D. Hanna, Feb 05 2012

Keywords

Comments

Also the number of partitions of n^2 into exactly n parts. - Seiichi Manyama, May 07 2018

Examples

			From _Seiichi Manyama_, May 07 2018: (Start)
n | Partitions of n^2 into exactly n parts
--+-------------------------------------------------------
1 | 1.
2 | 3+1 = 2+2.
3 | 7+1+1 = 6+2+1 = 5+3+1 = 5+2+2 = 4+4+1 = 4+3+2 = 3+3+3. (End)
		

Crossrefs

Programs

  • Maple
    T:= proc(n, k) option remember;
          `if`(n=0 or k=1, 1, T(n, k-1) + `if`(k>n, 0, T(n-k, k)))
        end:
    seq(T(n^2-n, n), n=0..20); # Vaclav Kotesovec, May 25 2015 after Alois P. Heinz
  • Mathematica
    Table[SeriesCoefficient[Product[1/(1-x^k),{k,1,n}],{x,0,n*(n-1)}],{n,0,20}] (* Vaclav Kotesovec, May 25 2015 *)
  • PARI
    {a(n)=polcoeff(prod(k=1,n,1/(1-x^k+x*O(x^(n^2-n)))),n^2-n)}
    for(n=0,30,print1(a(n),", "))

Formula

a(n) = [x^(n^2-n)] Product_{k=1..n} 1/(1 - x^k).
a(n) ~ c * d^n / n^2, where d = 9.153370192454122461948530292401354540073... = A258268, c = 0.07005383646855329845970382163053268... . - Vaclav Kotesovec, Sep 07 2014

A258293 Number of partitions of 3*n^2 into parts that are at most n.

Original entry on oeis.org

1, 1, 7, 75, 1033, 16019, 269005, 4767088, 87914929, 1671580383, 32560379840, 646795901962, 13058489343812, 267268692575830, 5534279506641422, 115754904055926892, 2442438538492842691, 51934447672016653655, 1111872048730513043539, 23949840661000275507964
Offset: 0

Views

Author

Vaclav Kotesovec, May 25 2015

Keywords

Crossrefs

Programs

  • Maple
    T:=proc(n, k) option remember; `if`(n=0 or k=1, 1, T(n, k-1) + `if`(n
    				
  • Mathematica
    (* A program to compute the constant d = 23.98280768... *) With[{j=3}, r^(2*j+1)/(r-1) /.FindRoot[-PolyLog[2,1-r] == (j+1/2)*Log[r]^2, {r, E}, WorkingPrecision->100]] (* Vaclav Kotesovec, Jun 10 2015 *)

Formula

a(n) ~ c * d^n / n^2, where d = 23.98280768122086592445663786762351573848..., c = 0.0530017980244665552354063060738409813... .

A258294 Number of partitions of 4*n^2 into parts that are at most n.

Original entry on oeis.org

1, 1, 9, 127, 2280, 46262, 1015691, 23541165, 567852809, 14123231487, 359874480333, 9351900623083, 247006639629275, 6613877399621729, 179171447281396640, 4902895256737984134, 135346525073067516814, 3765244155890019687101, 105465364199865165010867
Offset: 0

Views

Author

Vaclav Kotesovec, May 25 2015

Keywords

Crossrefs

Programs

  • Maple
    T:=proc(n, k) option remember; `if`(n=0 or k=1, 1, T(n, k-1) + `if`(n
    				
  • Mathematica
    (* A program to compute the constant d = 31.37931997... *) With[{j=4}, r^(2*j+1)/(r-1) /.FindRoot[-PolyLog[2,1-r] == (j+1/2)*Log[r]^2, {r, E}, WorkingPrecision->100]] (* Vaclav Kotesovec, Jun 10 2015 *)

Formula

a(n) ~ c * d^n / n^2, where d = 31.379319973863251370746442877119704410889..., c = 0.0397666338404544208556554596295683858... .

A258295 Number of partitions of 5*n^2 into parts that are at most n.

Original entry on oeis.org

1, 1, 11, 192, 4263, 106852, 2897747, 82966258, 2472338185, 75966810293, 2391508958235, 76782438832425, 2505642670439980, 82893573492724961, 2774547946438608789, 93807671621922558215, 3199617653993448321146, 109979504522862990517172, 3806257106793028952525938
Offset: 0

Views

Author

Vaclav Kotesovec, May 25 2015

Keywords

Crossrefs

Programs

  • Maple
    T:=proc(n, k) option remember; `if`(n=0 or k=1, 1, T(n, k-1) + `if`(n
    				
  • Mathematica
    (* A program to compute the constant d = 38.7729855... *) With[{j=5}, r^(2*j+1)/(r-1) /.FindRoot[-PolyLog[2,1-r] == (j+1/2)*Log[r]^2, {r, E}, WorkingPrecision->100]] (* Vaclav Kotesovec, Jun 10 2015 *)

Formula

a(n) ~ c * d^n / n^2, where d = 38.7729855097144987072847461256815071909..., c = 0.0318193213988281353709268311928... .

A258296 Number of partitions of 2*n^2 into parts that are at most n.

Original entry on oeis.org

1, 1, 5, 37, 351, 3765, 43752, 536375, 6842599, 89984614, 1212199424, 16651935901, 232477235048, 3290090540717, 47106320777132, 681247106742555, 9938641464083052, 146113228303254020, 2162784490438698636, 32209221982817148364, 482304350308369699381
Offset: 0

Views

Author

Vaclav Kotesovec, May 25 2015

Keywords

Crossrefs

Programs

  • Maple
    T:=proc(n,k) option remember; `if`(n=0 or k=1, 1, T(n,k-1) + `if`(n
    				
  • Mathematica
    (* A program to compute the constant d = 16.5796212... *) With[{j=2}, r^(2*j+1)/(r-1) /.FindRoot[-PolyLog[2,1-r] == (j+1/2)*Log[r]^2, {r, E}, WorkingPrecision->100]] (* Vaclav Kotesovec, Jun 10 2015 *)

Formula

a(n) ~ c * d^n / n^2, where d = 16.57962120993269533568313969522872808998..., c = 0.07942450354657307077058855728600800998... .

A206227 Number of partitions of n^2+n into parts not greater than n.

Original entry on oeis.org

1, 1, 4, 19, 108, 674, 4494, 31275, 225132, 1662894, 12541802, 96225037, 748935563, 5900502806, 46976736513, 377425326138, 3056671009814, 24930725879856, 204623068332997, 1688980598900228, 14012122025369431, 116784468316023069, 977437078888272796, 8212186058546599006
Offset: 0

Views

Author

Paul D. Hanna, Feb 05 2012

Keywords

Crossrefs

Programs

  • Maple
    T:= proc(n, k) option remember;
          `if`(n=0 or k=1, 1, T(n, k-1) + `if`(k>n, 0, T(n-k, k)))
        end:
    seq(T(n^2+n, n), n=0..20); # Vaclav Kotesovec, May 25 2015 after Alois P. Heinz
  • Mathematica
    Table[SeriesCoefficient[Product[1/(1-x^k),{k,1,n}],{x,0,n*(n+1)}],{n,0,20}] (* Vaclav Kotesovec, May 25 2015 *)
  • PARI
    {a(n)=polcoeff(prod(k=1,n,1/(1-x^k+x*O(x^(n^2+n)))),n^2+n)}
    for(n=0,30,print1(a(n),", "))

Formula

a(n) = [x^(n^2+n)] Product_{k=1..n} 1/(1 - x^k).
a(n) ~ c * d^n / n^2, where d = 9.1533701924541224619485302924013545... = A258268, c = 0.3572966225745094270279188015952797... . - Vaclav Kotesovec, Sep 07 2014

A321139 a(n) = [x^(n^2)] Product_{k=1..n} Sum_{m>=0} x^(k*m^2).

Original entry on oeis.org

1, 1, 1, 3, 7, 17, 52, 144, 480, 1732, 5902, 21078, 78434, 289107, 1079949, 4094643, 15574377, 59667023, 230318968, 892694240, 3477119540, 13606993083, 53438614380, 210622413188, 832922044686, 3303392730698, 13137474884294, 52381331536536, 209340904575968
Offset: 0

Views

Author

Seiichi Manyama, Oct 28 2018

Keywords

Comments

Also the number of nonnegative integer solutions (a_1, a_2, ... , a_n) to the equation a_1^2 + 2*a_2^2 + ... + n*a_n^2 = n^2.

Examples

			1*0^2 + 2*1^2 + 3*1^2 + 4*0^2 + 5*2^2 = 25.
1*0^2 + 2*2^2 + 3*2^2 + 4*0^2 + 5*1^2 = 25.
1*0^2 + 2*3^2 + 3*1^2 + 4*1^2 + 5*0^2 = 25.
1*1^2 + 2*0^2 + 3*0^2 + 4*1^2 + 5*2^2 = 25.
1*1^2 + 2*0^2 + 3*1^2 + 4*2^2 + 5*1^2 = 25.
1*1^2 + 2*2^2 + 3*0^2 + 4*2^2 + 5*0^2 = 25.
1*1^2 + 2*2^2 + 3*2^2 + 4*1^2 + 5*0^2 = 25.
1*2^2 + 2*0^2 + 3*0^2 + 4*2^2 + 5*1^2 = 25.
1*2^2 + 2*0^2 + 3*2^2 + 4*1^2 + 5*1^2 = 25.
1*2^2 + 2*1^2 + 3*1^2 + 4*2^2 + 5*0^2 = 25.
1*2^2 + 2*3^2 + 3*1^2 + 4*0^2 + 5*0^2 = 25.
1*3^2 + 2*0^2 + 3*0^2 + 4*2^2 + 5*0^2 = 25.
1*3^2 + 2*0^2 + 3*2^2 + 4*1^2 + 5*0^2 = 25.
1*3^2 + 2*2^2 + 3*1^2 + 4*0^2 + 5*1^2 = 25.
1*4^2 + 2*0^2 + 3*0^2 + 4*1^2 + 5*1^2 = 25.
1*4^2 + 2*1^2 + 3*1^2 + 4*1^2 + 5*0^2 = 25.
1*5^2 + 2*0^2 + 3*0^2 + 4*0^2 + 5*0^2 = 25.
So a(5) = 17.
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember; local j; if n=0 then 1
          elif i<1 then 0 else b(n, i-1); for j while
            i*j^2<=n do %+b(n-i*j^2, i-1) od; % fi
        end:
    a:= n-> b(n^2, n):
    seq(a(n), n=0..30);  # Alois P. Heinz, Oct 28 2018
  • Mathematica
    nmax = 25; Table[SeriesCoefficient[Product[(EllipticTheta[3, 0, x^k] + 1)/2, {k, 1, n}], {x, 0, n^2}], {n, 0, nmax}] (* Vaclav Kotesovec, Oct 29 2018 *)
  • PARI
    {a(n) = polcoeff(prod(i=1, n, sum(j=0, sqrtint(n^2\i), x^(i*j^2)+x*O(x^(n^2)))), n^2)}

Formula

a(n) = [x^(n^2)] Product_{k=1..n} (theta_3(x^k) + 1)/2, where theta_3() is the Jacobi theta function.
Showing 1-10 of 12 results. Next