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 1-4 of 4 results.

A300785 Triangle read by rows: T(n,k) = 140*k^3*(n-k)^3 - 14*k*(n-k) + 1; n >= 0, 0 <= k <= n.

Original entry on oeis.org

1, 1, 1, 1, 127, 1, 1, 1093, 1093, 1, 1, 3739, 8905, 3739, 1, 1, 8905, 30157, 30157, 8905, 1, 1, 17431, 71569, 101935, 71569, 17431, 1, 1, 30157, 139861, 241753, 241753, 139861, 30157, 1, 1, 47923, 241753, 472291, 573217, 472291, 241753, 47923, 1, 1, 71569, 383965, 816229, 1119721, 1119721, 816229, 383965, 71569, 1
Offset: 0

Views

Author

Kolosov Petro, Mar 12 2018

Keywords

Comments

From Kolosov Petro, Apr 12 2020: (Start)
Let A(m, r) = A302971(m, r) / A304042(m, r).
Let L(m, n, k) = Sum_{r=0..m} A(m, r) * k^r * (n - k)^r.
Then T(n, k) = L(3, n, k).
T(n, k) is symmetric: T(n, k) = T(n, n-k). (End)

Examples

			Triangle begins:
--------------------------------------------------------------------
k=   0      1       2       3       4       5       6      7     8
--------------------------------------------------------------------
n=0: 1;
n=1: 1,     1;
n=2: 1,   127,      1;
n=3: 1,  1093,   1093,      1;
n=4: 1,  3739,   8905,   3739,      1;
n=5: 1,  8905,  30157,  30157,   8905,      1;
n=6: 1, 17431,  71569, 101935,  71569,  17431,      1;
n=7: 1, 30157, 139861, 241753, 241753, 139861,  30157,     1;
n=8: 1, 47923, 241753, 472291, 573217, 472291, 241753, 47923,    1;
		

Crossrefs

Various cases of L(m, n, k): A287326 (m=1), A300656 (m=2), This sequence (m=3). See comments for L(m, n, k).
Row sums give A258806.

Programs

  • GAP
    T:=Flat(List([0..9], n->List([0..n], k->140*k^3*(n-k)^3 - 14*k*(n-k)+1))); # G. C. Greubel, Dec 14 2018
  • Magma
    /* As triangle */ [[140*k^3*(n-k)^3-14*k*(n-k)+1: k in [0..n]]: n in [0..10]]; // Bruno Berselli, Mar 21 2018
    
  • Maple
    T:=(n,k)->140*k^3*(n-k)^3-14*k*(n-k)+1: seq(seq(T(n,k),k=0..n),n=0..9); # Muniru A Asiru, Dec 14 2018
  • Mathematica
    T[n_, k_] := 140*k^3*(n - k)^3 - 14*k*(n - k) + 1; Column[
    Table[T[n, k], {n, 0, 10}, {k, 0, n}], Center] (* From Kolosov Petro, Apr 12 2020 *)
  • PARI
    t(n, k) = 140*k^3*(n-k)^3-14*k*(n-k)+1
    trianglerows(n) = for(x=0, n-1, for(y=0, x, print1(t(x, y), ", ")); print(""))
    /* Print initial 9 rows of triangle as follows */ trianglerows(9)
    
  • Sage
    [[140*k^3*(n-k)^3 - 14*k*(n-k)+1 for k in range(n+1)] for n in range(12)] # G. C. Greubel, Dec 14 2018
    

Formula

From Kolosov Petro, Apr 12 2020: (Start)
T(n, k) = 140*k^3*(n-k)^3 - 14*k*(n-k) + 1.
T(n, k) = 140*A094053(n, k)^3 + 0*A094053(n, k)^2 - 14*A094053(n, k)^1 + 1.
T(n+3, k) = 4*T(n+2, k) - 6*T(n+1, k) + 4*T(n, k) - T(n-1, k), for n >= k.
Sum_{k=1..n} T(n, k) = A001015(n).
Sum_{k=0..n} T(n, k) = A258806(n).
Sum_{k=0..n-1} T(n, k) = A001015(n).
Sum_{k=1..n-1} T(n, k) = A258808(n).
Sum_{k=1..n-1} T(n, k) = -A024005(n).
Sum_{k=1..r} T(n, k) = -A316387(3, r, 0)*n^0 + A316387(3, r, 1)*n^1 - A316387(3, r, 2)*n^2 + A316387(3, r, 3)*n^3. (End)
G.f.: (1 + 127*x^6*y^3 - 3*x*(1 + y) + 585*x^5*y^2*(1 + y) + 129*x^4*y*(1 + 17*y + y^2) + 3*x^2*(1 + 45*y + y^2) - x^3*(1 - 579*y - 579*y^2 + y^3))/((1 - x)^4*(1 - x*y)^4). - Stefano Spezia, Sep 14 2024

A195859 a(n) = n^8-n.

Original entry on oeis.org

0, 0, 254, 6558, 65532, 390620, 1679610, 5764794, 16777208, 43046712, 99999990, 214358870, 429981684, 815730708, 1475789042, 2562890610, 4294967280, 6975757424, 11019960558, 16983563022, 25599999980, 37822859340, 54875873514, 78310985258, 110075314152
Offset: 0

Views

Author

Vincenzo Librandi, Sep 30 2011

Keywords

Programs

  • Magma
    [(n^8-n): n in [0..30]];
    
  • Mathematica
    Table[n^8 - n, {n, 0, 40}] (* and *) LinearRecurrence[{9, -36, 84, -126, 126, -84, 36, -9, 1}, {0, 0, 254, 6558, 65532, 390620, 1679610, 5764794, 16777208}, 40] (* Vladimir Joseph Stephan Orlovsky, Feb 21 2012 *)
  • PARI
    a(n)=n^8-n \\ Charles R Greathouse IV, Oct 07 2015

Formula

G.f.: -2*x^2*(127+2136*x+7827*x^2+7792*x^3+2157*x^4+120*x^5+x^6) / ( (x-1)^9 ). - R. J. Mathar, Sep 30 2011
a(n) = -n*A024005(n).

A258837 a(n) = 1 - n^2.

Original entry on oeis.org

1, 0, -3, -8, -15, -24, -35, -48, -63, -80, -99, -120, -143, -168, -195, -224, -255, -288, -323, -360, -399, -440, -483, -528, -575, -624, -675, -728, -783, -840, -899, -960, -1023, -1088, -1155, -1224, -1295, -1368, -1443, -1520, -1599, -1680, -1763, -1848
Offset: 0

Views

Author

Vincenzo Librandi, Jun 12 2015

Keywords

Crossrefs

Sequences of the type 1-n^k: A024000 (k=1), this sequence (k=2), A024001 (k=3), A024002 (k=4), A024003 (k=5), A024004 (k=6), A024005 (k=7), A024006 (k=8), A024007 (k=9), A024008 (k=10), A024009 (k=11), A024010 (k=12).

Programs

  • Magma
    [1-n^2: n in [0..50]];
    
  • Magma
    I:=[1,0,-3]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+Self(n-3): n in [1..50]];
    
  • Mathematica
    Table[1 - n^2, {n, 0, 50}] (* or *) LinearRecurrence[{3, -3, 1}, {1, 0, -3}, 50]
  • PARI
    my(x='x+O('x^50)); Vec((1-3*x)/(1-x)^3) \\ G. C. Greubel, May 11 2017

Formula

G.f.: (1-3*x)/(1-x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).
a(n) = -A067998(n+1). - Joerg Arndt, Jun 13 2015
a(n) = (-1)^n*A131386(n+1). - Bruno Berselli, Jun 15 2015
E.g.f.: (1 - x - x^2)*exp(x). - G. C. Greubel, May 11 2017
Sum_{n>=2} 1/a(n) = -3/4. - Amiram Eldar, Feb 17 2023

A258808 a(n) = n^7 - 1.

Original entry on oeis.org

0, 127, 2186, 16383, 78124, 279935, 823542, 2097151, 4782968, 9999999, 19487170, 35831807, 62748516, 105413503, 170859374, 268435455, 410338672, 612220031, 893871738, 1279999999, 1801088540, 2494357887, 3404825446, 4586471423, 6103515624, 8031810175
Offset: 1

Views

Author

Vincenzo Librandi, Jun 11 2015

Keywords

Crossrefs

Subsequence of A181126.
Cf. A258806.
Cf. similar sequences listed in A258807.

Programs

  • Magma
    [n^7-1: n in [1..40]];
    
  • Magma
    I:=[0,127,2186,16383, 78124,279935,823542,2097151]; [n le 8 select I[n] else 8*Self(n-1) - 28*Self(n-2)+56*Self(n-3)-70*Self(n-4)+56*Self(n-5) - 28*Self(n-6) +8*Self(n-7)-Self(n-8): n in [1..40]];
    
  • Mathematica
    Table[n^7 - 1, {n, 1, 40}] (* or *) LinearRecurrence[{8, -28, 56, -70, 56, -28, 8, -1}, {0, 127, 2186, 16383, 78124, 279935, 823542, 2097151}, 40]
  • Sage
    [n^7-1 for n in (1..40)] # Bruno Berselli, Jun 11 2015

Formula

G.f.: x^2*(127 + 1170*x + 2451*x^2 + 1156*x^3 + 141*x^4 - 6*x^5 + x^6)/(1 - x)^8.
a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8).
a(n) = -A024005(n). [Bruno Berselli, Jun 11 2015]
a(n) = (n-1)*A053716(n). - Michel Marcus, Aug 21 2015
Showing 1-4 of 4 results.