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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A277529 Decimal expansion of the eighth derivative of the infinite power tower function x^x^x... at x = 1/2, negated.

Original entry on oeis.org

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

Views

Author

Alois P. Heinz, Oct 19 2016

Keywords

Examples

			-50109.2762750366968958680172353229451272183942...
		

Crossrefs

Programs

  • Mathematica
    f[x_] := -ProductLog[-Log[x]]/Log[x]; RealDigits[Derivative[8][f][1/2], 10, 120][[1]] (* Amiram Eldar, May 23 2023 *)

A277530 Decimal expansion of the ninth derivative of the infinite power tower function x^x^x... at x = 1/2.

Original entry on oeis.org

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

Views

Author

Alois P. Heinz, Oct 19 2016

Keywords

Examples

			844617.08671093611975158207114938322395461002...
		

Crossrefs

Programs

  • Mathematica
    f[x_] := -ProductLog[-Log[x]]/Log[x]; RealDigits[Derivative[9][f][1/2], 10, 120][[1]] (* Amiram Eldar, May 23 2023 *)

A277531 Decimal expansion of the tenth derivative of the infinite power tower function x^x^x... at x = 1/2, negated.

Original entry on oeis.org

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

Views

Author

Alois P. Heinz, Oct 19 2016

Keywords

Examples

			-14109508.6045782521667480795666213861159276...
		

Crossrefs

Programs

  • Mathematica
    f[x_] := -ProductLog[-Log[x]]/Log[x]; RealDigits[Derivative[10][f][1/2], 10, 120][[1]] (* Amiram Eldar, May 23 2023 *)

A216349 Triangle T(n,k) in which n-th row lists the values of the n-th derivative at x=1 of all functions that are representable as x^x^...^x with n x's and parentheses inserted in all possible ways; n>=1, 1<=k<=A000081(n).

Original entry on oeis.org

1, 2, 12, 9, 156, 100, 80, 56, 3160, 1880, 1180, 1420, 950, 1360, 890, 660, 480, 87990, 50496, 29682, 35382, 24042, 22008, 14928, 31968, 20268, 14988, 10848, 34974, 21474, 13314, 15114, 10974, 13014, 8874, 6534, 5094, 3218628, 1806476, 1021552, 588756, 1189132
Offset: 1

Views

Author

Alois P. Heinz, Sep 04 2012

Keywords

Comments

The ordering of the functions is the same as in A215703 and is defined by the algorithm below.

Examples

			For n=4 the A000081(4) = 4 functions and their 4th derivatives at x=1 are x^(x^3)->156, x^(x^x*x)->100, x^(x^(x^2))->80, x^(x^(x^x))->56.
Triangle T(n,k) begins:
:     1;
:     2;
:    12,     9;
:   156,   100,    80,    56;
:  3160,  1880,  1180,  1420,   950,  1360,   890,   660,   480;
: 87990, 50496, 29682, 35382, 24042, 22008, 14928, 31968, 20268, ...
		

Crossrefs

First column gives: A216351.
Last elements of rows give: A033917.
A version with sorted row elements is: A216350.
Rows sums give: A216281.

Programs

  • Maple
    with(combinat):
    F:= proc(n) F(n):= `if`(n<2, [x$n], map(h->x^h, g(n-1, n-1))) end:
    g:= proc(n, i) option remember; `if`(n=0 or i=1, [x^n],
         `if`(i<1, [], [seq(seq(seq(mul(F(i)[w[t]-t+1], t=1..j)*v,
          w=choose([$1..nops(F(i))+j-1], j)), v=g(n-i*j, i-1)), j=0..n/i)]))
        end:
    T:= n-> map(f-> n!*coeff(series(subs(x=x+1, f), x, n+1), x, n), F(n))[]:
    seq(T(n), n=1..7);

A216350 Triangle T(n,k) in which n-th row lists in increasing order the values of the n-th derivative at x=1 of all functions that are representable as x^x^...^x with n x's and parentheses inserted in all possible ways; n>=1, 1<=k<=A000081(n).

Original entry on oeis.org

1, 2, 9, 12, 56, 80, 100, 156, 480, 660, 890, 950, 1180, 1360, 1420, 1880, 3160, 5094, 6534, 8874, 10848, 10974, 13014, 13314, 14928, 14988, 15114, 20268, 21474, 22008, 24042, 29682, 31968, 34974, 35382, 50496, 87990, 65534, 78134, 102494, 131684, 141974
Offset: 1

Views

Author

Alois P. Heinz, Sep 04 2012

Keywords

Examples

			For n=4 the A000081(4) = 4 functions and their 4th derivatives at x=1 are x^(x^3)->156, x^(x^x*x)->100, x^(x^(x^2))->80, x^(x^(x^x))->56 => 4th row = [56, 80, 100, 156].
Triangle T(n,k) begins:
:    1;
:    2;
:    9,   12;
:   56,   80,  100,   156;
:  480,  660,  890,   950,  1180,  1360,  1420,  1880,  3160;
: 5094, 6534, 8874, 10848, 10974, 13014, 13314, 14928, 14988, 15114, ...
		

Crossrefs

First column gives: A033917.
Last elements of rows give: A216351.
A version with different ordering of row elements is: A216349.
Rows sums give: A216281.

Programs

  • Maple
    with(combinat):
    F:= proc(n) F(n):= `if`(n<2, [x$n], map(h->x^h, g(n-1, n-1))) end:
    g:= proc(n, i) option remember; `if`(n=0 or i=1, [x^n],
         `if`(i<1, [], [seq(seq(seq(mul(F(i)[w[t]-t+1], t=1..j)*v,
          w=choose([$1..nops(F(i))+j-1], j)), v=g(n-i*j, i-1)), j=0..n/i)]))
        end:
    T:= n-> sort(map(f-> n!*coeff(series(subs(x=x+1, f)
                     , x, n+1), x, n), F(n)))[]:
    seq(T(n), n=1..7);

A349505 E.g.f. satisfies: A(x) = (1 + x)^(A(x)^3).

Original entry on oeis.org

1, 1, 6, 81, 1668, 46740, 1659102, 71386602, 3611376360, 210083758704, 13817649943440, 1013979735381888, 82134894774767832, 7279520816638839600, 700730732176038359208, 72803537907677356262760, 8120227815636769492383168
Offset: 0

Views

Author

Seiichi Manyama, Nov 20 2021

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 20; CoefficientList[Series[(-LambertW[-3*Log[1 + x]]/(3*Log[1 + x]))^(1/3), {x, 0, nmax}], x]*Range[0, nmax]! (* Vaclav Kotesovec, Nov 20 2021 *)
  • PARI
    a(n) = sum(k=0, n, (3*k+1)^(k-1)*stirling(n, k, 1));
    
  • PARI
    N=20; x='x+O('x^N); Vec(serlaplace(sum(k=0, N, (3*k+1)^(k-1)*log(1+x)^k/k!)))

Formula

a(n) = Sum_{k=0..n} (3*k+1)^(k-1) * Stirling1(n,k).
E.g.f. A(x) = Sum_{k>=0} (3*k+1)^(k-1) * (log(1+x))^k / k!.
From Vaclav Kotesovec, Nov 20 2021: (Start)
E.g.f.: (-LambertW(-3*log(1 + x)) / (3*log(1 + x)))^(1/3).
a(n) ~ n^(n-1) / (sqrt(3) * (exp(exp(-1)/3) - 1)^(n - 1/2) * exp(n + exp(-1)/6 - 5/6)). (End)

A277536 T(n,k) is the n-th derivative of the difference between the k-th tetration of x (power tower of order k) and its predecessor (or 0 if k=0) at x=1; triangle T(n,k), n>=0, 0<=k<=n, read by rows.

Original entry on oeis.org

1, 0, 1, 0, 0, 2, 0, 0, 3, 6, 0, 0, 8, 24, 24, 0, 0, 10, 170, 180, 120, 0, 0, 54, 900, 1980, 1440, 720, 0, 0, -42, 6566, 19530, 21840, 12600, 5040, 0, 0, 944, 44072, 224112, 305760, 248640, 120960, 40320, 0, 0, -5112, 365256, 2650536, 4818744, 4536000, 2993760, 1270080, 362880
Offset: 0

Views

Author

Alois P. Heinz, Oct 19 2016

Keywords

Comments

T(n,k) is defined for all n,k >= 0. The triangle contains only the terms with k<=n. T(n,k) = 0 for k>n.

Examples

			Triangle T(n,k) begins:
  1;
  0, 1;
  0, 0,   2;
  0, 0,   3,     6;
  0, 0,   8,    24,     24;
  0, 0,  10,   170,    180,    120;
  0, 0,  54,   900,   1980,   1440,    720;
  0, 0, -42,  6566,  19530,  21840,  12600,   5040;
  0, 0, 944, 44072, 224112, 305760, 248640, 120960, 40320;
  ...
		

Crossrefs

Columns k=0-2 give: A000007, A063524, A005727 (for n>1).
Main diagonal gives A000142.
Row sums give A033917.
T(n+1,n)/3 gives A005990.
T(2n,n) gives A290023.

Programs

  • Maple
    f:= proc(n) option remember; `if`(n<0, 0,
          `if`(n=0, 1, (x+1)^f(n-1)))
        end:
    T:= (n, k)-> n!*coeff(series(f(k)-f(k-1), x, n+1), x, n):
    seq(seq(T(n, k), k=0..n), n=0..12);
    # second Maple program:
    b:= proc(n, k) option remember; `if`(n=0, 1, `if`(k=0, 0,
          -add(binomial(n-1, j)*b(j, k)*add(binomial(n-j, i)*
          (-1)^i*b(n-j-i, k-1)*(i-1)!, i=1..n-j), j=0..n-1)))
        end:
    T:= (n, k)-> b(n, min(k, n))-`if`(k=0, 0, b(n, min(k-1, n))):
    seq(seq(T(n, k), k=0..n), n=0..12);
  • Mathematica
    f[n_] := f[n] = If[n < 0, 0, If[n == 0, 1, (x + 1)^f[n - 1]]];
    T[n_, k_] := n!*SeriesCoefficient[f[k] - f[k - 1], { x, 0, n}];
    Table[T[n, k], {n, 0, 12}, {k, 0, n}] // Flatten
    (* second program: *)
    b[n_, k_] := b[n, k] = If[n == 0, 1, If[k == 0, 0, -Sum[Binomial[n - 1, j]*b[j, k]*Sum[Binomial[n - j, i]*(-1)^i*b[n - j - i, k - 1]*(i - 1)!, {i, 1, n - j}], {j, 0, n - 1}]]];
    T[n_, k_] := (b[n, Min[k, n]] - If[k == 0, 0, b[n, Min[k - 1, n]]]);
    Table[T[n, k], {n, 0, 12}, {k, 0, n}] // Flatten (* Jean-François Alcover, May 28 2018, from Maple *)

Formula

E.g.f. of column k>0: (x+1)^^k - (x+1)^^(k-1), e.g.f. of column k=0: 1.
T(n,k) = [(d/dx)^n (x^^k - x^^(k-1))]_{x=1} for k>0, T(n,0) = A000007(n).
T(n,k) = A277537(n,k) - A277537(n,k-1) for k>0, T(n,0) = A000007(n).
T(n,k) = n * A295027(n,k) for n,k > 0.

A349504 E.g.f. satisfies: A(x) = (1 + x)^(A(x)^2).

Original entry on oeis.org

1, 1, 4, 36, 484, 8840, 203868, 5691308, 186612592, 7031373264, 299397454080, 14218443479328, 745142534904480, 42717896158340832, 2659373970144454080, 178666030775042040000, 12884568940594969258752, 992750028716940749121792
Offset: 0

Views

Author

Seiichi Manyama, Nov 20 2021

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 20; CoefficientList[Series[Sqrt[-LambertW[-2*Log[1 + x]]/(2*Log[1 + x])], {x, 0, nmax}], x] * Range[0, nmax]! (* Vaclav Kotesovec, Nov 20 2021 *)
  • PARI
    a(n) = sum(k=0,n, (2*k+1)^(k-1)*stirling(n, k, 1));
    
  • PARI
    N=20; x='x+O('x^N); Vec(serlaplace(sum(k=0, N, (2*k+1)^(k-1)*log(1+x)^k/k!)))

Formula

a(n) = Sum_{k=0..n} (2*k+1)^(k-1) * Stirling1(n,k).
E.g.f. A(x) = Sum_{k>=0} (2*k+1)^(k-1) * (log(1+x))^k / k!.
From Vaclav Kotesovec, Nov 20 2021: (Start)
E.g.f.: sqrt(-LambertW(-2*log(1 + x)) / (2*log(1 + x))).
a(n) ~ n^(n-1) / (sqrt(2) * (exp(exp(-1)/2) - 1)^(n - 1/2) * exp(n + exp(-1)/4 - 1)). (End)

A136461 Expansion of e.g.f.: A(x) = -(1 + LambertW(-log(1+x))/log(1+x))/x.

Original entry on oeis.org

1, 1, 3, 14, 96, 849, 9362, 123101, 1888016, 33066768, 651883152, 14286514186, 344690210928, 9079702374300, 259327537407416, 7983107543564724, 263518937698466304, 9285770278110061664, 347916420499685643072, 13812127364516107258944, 579183295530010157485824
Offset: 0

Views

Author

Paul D. Hanna, Dec 31 2007

Keywords

Comments

A033917 gives the coefficients of iterated exponential function defined by y(x) = x^y(x) expanded about x=1.

Crossrefs

Cf. A033917.
Row sums of A295027 (shifted).
Main diagonal of A295028 (shifted).

Programs

  • Maple
    a:= n-> add(Stirling1(n+1, k)*(k+1)^(k-1), k=0..n+1)/(n+1):
    seq(a(n), n=0..25);  # Alois P. Heinz, Jan 21 2016
  • Mathematica
    CoefficientList[Series[-(1+LambertW[-Log[1+x]]/Log[1+x])/x, {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Nov 27 2012 *)
  • PARI
    {a(n)=n!*polcoeff(sum(i=0,n+1,(i+1)^(i-1)*log(1+x +O(x^(n+2) ))^i/i!), n+1)}
    
  • PARI
    x='x+O('x^30); Vec(serlaplace(-(1+lambertw(-log(1+x))/log(1+x))/x  )) \\ G. C. Greubel, Feb 19 2018

Formula

a(n) = A033917(n+1)/(n+1).
E.g.f.: A(x) = (1/x)*Sum_{i>=1} (i+1)^(i-1) * log(1+x)^i/i!.
a(n) ~ n^(n-1) / ( exp(n-3/2+exp(-1)/2) * (exp(exp(-1))-1)^(n+1/2) ). - Vaclav Kotesovec, Nov 27 2012

A277541 n-th derivative of the tenth tetration of x (power tower of order 10) x^^10 at x=1.

Original entry on oeis.org

1, 1, 2, 9, 56, 480, 5094, 65534, 984808, 16992144, 330667680, 7130797872, 168564160632, 4321664793264, 119356965323400, 3528831476247240, 111173720474673984, 3716755785886791168, 131414199676568655552, 4899052003032070987968, 192050612714621129114880
Offset: 0

Views

Author

Alois P. Heinz, Oct 19 2016

Keywords

Comments

Differs from A033917 first at n=11.

Crossrefs

Column k=10 of A277537.

Programs

  • Maple
    f:= proc(n) f(n):= `if`(n=0, 1, (x+1)^f(n-1)) end:
    a:= n-> n!*coeff(series(f(10), x, n+1), x, n):
    seq(a(n), n=0..25);
  • Mathematica
    f[n_] := f[n] = If[n == 0, 1, (x + 1)^f[n - 1]];
    a[n_] := n!*SeriesCoefficient[f[10], {x, 0, n}];
    Table[a[n], {n, 0, 25}] (* Jean-François Alcover, May 30 2018, from Maple *)

Formula

E.g.f.: (x+1)^^10.
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