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.

Previous Showing 11-17 of 17 results.

A024208 Number of terms in n-th derivative of a function composed with itself 8 times.

Original entry on oeis.org

1, 1, 8, 36, 148, 498, 1590, 4586, 12644, 32775, 81901, 196085, 455772, 1025779, 2252674, 4823546, 10116553, 20783490, 41949270, 83211931, 162552093, 312850854, 594086542, 1113610526, 2062796698, 3777567977, 6844786250, 12276620372, 21809737429, 38391720375
Offset: 0

Views

Author

Winston C. Yang (yang(AT)math.wisc.edu)

Keywords

References

  • W. C. Yang (yang(AT)math.wisc.edu), Derivatives of self-compositions of functions, preprint, 1997.

Crossrefs

Cf. A008778, A022811-A022817, A024207-A024210. First column of A050302.
Column k=8 of A022818.

Programs

  • Mathematica
    b[n_, i_, k_] := b[n, i, k] = If[nJean-François Alcover, Apr 28 2017, after Alois P. Heinz *)

Formula

If a(n,m) = number of terms in m-derivative of a function composed with itself n times, p(n,k) = number of partitions of n into k parts, then a(n,m) = sum_{i=0..m} p(m,i)*a(n-1,i).

A024209 Number of terms in n-th derivative of a function composed with itself 9 times.

Original entry on oeis.org

1, 1, 9, 45, 201, 735, 2517, 7785, 22857, 63024, 166819, 422537, 1035971, 2456694, 5672347, 12756334, 28053280, 60371967, 127479247, 264311585, 539102751, 1082474167, 2142579168, 4183251750, 8064722973, 15360809911, 28928858208, 53896616704, 99398216733
Offset: 0

Views

Author

Winston C. Yang (yang(AT)math.wisc.edu)

Keywords

References

  • W. C. Yang (yang(AT)math.wisc.edu), Derivatives of self-compositions of functions, preprint, 1997.

Crossrefs

Cf. A008778, A022811-A022817, A024207-A024210. First column of A050303.
Column k=9 of A022818.

Programs

  • Mathematica
    b[n_, i_, k_] := b[n, i, k] = If[nJean-François Alcover, Apr 28 2017, after Alois P. Heinz *)

Formula

If a(n,m) = number of terms in m-derivative of a function composed with itself n times, p(n,k) = number of partitions of n into k parts, then a(n,m) = sum_{i=0..m} p(m,i)*a(n-1,i).

A022816 Number of terms in 6th derivative of a function composed with itself n times.

Original entry on oeis.org

1, 11, 44, 121, 271, 532, 952, 1590, 2517, 3817, 5588, 7943, 11011, 14938, 19888, 26044, 33609, 42807, 53884, 67109, 82775, 101200, 122728, 147730, 176605, 209781, 247716, 290899, 339851, 395126, 457312, 527032, 604945, 691747
Offset: 1

Views

Author

Keywords

References

  • W. C. Yang (yang(AT)math.wisc.edu), Derivatives of self-compositions of functions, preprint, 1997.

Crossrefs

Programs

  • Magma
    [n*(n+1)*(n^3+24*n^2+81*n-46)/120: n in [1..40]]; // Vincenzo Librandi, Oct 10 2011
    
  • Mathematica
    Table[n(n+1)(n^3+24n^2+81n-46)/120,{n,40}] (* or *) LinearRecurrence[{6,-15,20,-15,6,-1},{1,11,44,121,271,532},40] (* Harvey P. Dale, Dec 29 2017 *)
  • PARI
    a(n)=n*(n+1)*(n^3+24*n^2+81*n-46)/120 \\ Charles R Greathouse IV, Oct 21 2022

Formula

a(n) = n*(n+1)*(n^3+24*n^2+81*n-46)/120. G.f.: x*(1+5*x-7*x^2+2*x^3)/(x-1)^6. - R. J. Mathar, Sep 15 2009

Extensions

More terms from Christian G. Bower, Aug 15 1999.

A192435 Number of terms in n-th derivative of a function composed with itself n times.

Original entry on oeis.org

1, 2, 6, 26, 110, 532, 2541, 12644, 63024, 318857, 1618947, 8277062, 42453073, 218597485, 1128527057, 5841301830, 30297014746, 157442596130, 819511659381, 4272054888643, 22299423992018, 116539878029773, 609718298887977, 3193136462042241, 16737951567806110
Offset: 1

Views

Author

Alois P. Heinz, Aug 18 2012

Keywords

Crossrefs

Main diagonal of A022818.
Cf. A008485.

Programs

  • Maple
    A:= proc(n, k) option remember;
          `if`(k=1, 1, add(b(n, n, i)*A(i, k-1), i=0..n))
        end:
    b:= proc(n, i, k) option remember; `if`(n A(n, n):
    seq(a(n), n=1..40);
  • Mathematica
    A[n_, k_] := A[n, k] = If[k == 1, 1, Sum[b[n, n, i]*A[i, k-1], {i, 0, n}]]; b[n_, i_, k_] := b[n, i, k] = If[nJean-François Alcover, Feb 05 2015, after Alois P. Heinz *)

Formula

a(n) ~ c * d^n / sqrt(n), where d = A270915 = 5.35270133348664..., c = 0.0504640078963302151598181537452... . - Vaclav Kotesovec, Sep 03 2014, updated May 19 2018

A215626 Number of terms in 8th derivative of a function composed with itself n times.

Original entry on oeis.org

1, 22, 129, 468, 1309, 3101, 6539, 12644, 22857, 39148, 64141, 101256, 154869, 230491, 334967, 476696, 665873, 914754, 1237945, 1652716, 2179341, 2841465, 3666499, 4686044, 5936345, 7458776, 9300357, 11514304, 14160613, 17306679, 21027951, 25408624, 30542369
Offset: 1

Views

Author

Alois P. Heinz, Aug 18 2012

Keywords

Crossrefs

Row n=8 of A022818.

Programs

  • Maple
    a:= n-> n*(n+6)*(92+(-713+(722+(568+(50+n)*n)*n)*n)*n)/5040:
    seq(a(n), n=1..40);
  • Mathematica
    CoefficientList[Series[(x^6-7x^5+15x^4-4x^3-19x^2+14x+1)x/(x-1)^8,{x,0,40}],x]//Rest (* Harvey P. Dale, Aug 02 2020 *)

Formula

G.f.: (x^6-7*x^5+15*x^4-4*x^3-19*x^2+14*x+1)*x/(x-1)^8.
a(n) = n*(n+6)*(n^5+50*n^4+568*n^3+722*n^2-713*n+92)/5040.

A215627 Number of terms in 9th derivative of a function composed with itself n times.

Original entry on oeis.org

1, 30, 210, 867, 2690, 6956, 15833, 32775, 63024, 114235, 197241, 326976, 523575, 813671, 1231910, 1822706, 2642259, 3760860, 5265508, 7262865, 9882576, 13280982, 17645255, 23197985, 30202250, 38967201, 49854195, 63283510, 79741677, 99789465, 124070556
Offset: 1

Views

Author

Alois P. Heinz, Aug 18 2012

Keywords

Crossrefs

Row n=9 of A022818.

Programs

  • Maple
    a:= n-> n*(n+1)*(6000+(-30788+(29472+(13697+(1703+(75+n)*n)*n)*n)*n)*n)/40320:
    seq(a(n), n=1..40);

Formula

G.f.: (5*x^6-28*x^5+53*x^4-27*x^3-24*x^2+21*x+1)*x/(1-x)^9.
a(n) = n*(n+1)*(n^6+75*n^5+1703*n^4+13697*n^3+29472*n^2-30788*n+6000)/40320.

A215628 Number of terms in 10th derivative of a function composed with itself n times.

Original entry on oeis.org

1, 42, 345, 1597, 5436, 15217, 37148, 81901, 166819, 318857, 578413, 1004224, 1679522, 2719666, 4281488, 6574614, 9875045, 14541308, 21033513, 29935679, 41981720, 58085511, 79375484, 107234235, 143343655, 189736131, 248852397, 323606650, 417459582, 534500016
Offset: 1

Views

Author

Alois P. Heinz, Aug 18 2012

Keywords

Crossrefs

Row n=10 of A022818.

Programs

  • Maple
    a:= n-> n*(n+1)*(136656+(-412380+(209204+(203887+(40826+(3148+(98+n)*
            n)*n)*n)*n)*n)*n)/362880:
    seq(a(n), n=1..40);
  • Mathematica
    CoefficientList[Series[-(4*x^7 - 34*x^6 + 110*x^5 - 161*x^4 + 83*x^3 + 30*x^2 - 32*x - 1)/(x - 1)^10, {x, 0, 30}], x] (* Wesley Ivan Hurt, Jan 27 2017 *)

Formula

G.f.: -(4*x^7-34*x^6+110*x^5-161*x^4+83*x^3+30*x^2-32*x-1)*x/(x-1)^10.
a(n) = n*(n+1)*(n^7 +98*n^6 +3148*n^5 +40826*n^4 +203887*n^3 +209204*n^2 -412380*n +136656) / 362880.
Previous Showing 11-17 of 17 results.