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 1-3 of 3 results.

A179298 a(n)=n^3-(n-1)^3-(n-2)^3-...-1.

Original entry on oeis.org

1, 7, 18, 28, 25, -9, -98, -272, -567, -1025, -1694, -2628, -3887, -5537, -7650, -10304, -13583, -17577, -22382, -28100, -34839, -42713, -51842, -62352, -74375, -88049, -103518, -120932, -140447, -162225, -186434, -213248, -242847, -275417
Offset: 1

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Author

Keywords

Comments

1^3-0=1, 2^3-1=7, 3^3-2^3-1=18, 4^3-3^3-2^3-1=28, 5^3-4^3-3^3-2^3-1=25, 6^3-5^3-4^3-3^3-2^3-1=-9,..

Crossrefs

Programs

  • Mathematica
    f[n_]:=Module[{k=n-1,x=n^3},While[k>0,x-=k^3;k--;];x];lst={};Do[AppendTo[lst,f[n]],{n,5!}];lst

Formula

a(n) = -n^2*(1-6*n+n^2)/4. G.f.: (2*x-1)*(x^2+4*x+1)/(x-1)^5. [From R. J. Mathar, Jul 11 2010]

A341331 a(n) = n^n - (n-1)^n - (n-2)^n - ... - 1^n.

Original entry on oeis.org

1, 3, 18, 158, 1825, 26141, 446782, 8869820, 200535993, 5085658075, 142947350986, 4410243535402, 148156328308105, 5382924338773177, 210309307208574750, 8791961076113491704, 391581231268402937041, 18510377905675629883959, 925555262359725659407258
Offset: 1

Views

Author

Seiichi Manyama, Feb 09 2021

Keywords

Crossrefs

Programs

  • Maple
    f:= proc(n) local k;  n^n - add(k^n,k=1..n-1) end proc:
    map(f, [$1..30]); # Robert Israel, Feb 10 2021
  • Mathematica
    a[n_] := n^n - Sum[k^n, {k, 0, n - 1}]; Array[a, 20] (* Amiram Eldar, Apr 28 2021 *)
  • PARI
    a(n) = n^n-sum(k=0, n-1, k^n);

Formula

a(n) = A000312(n) - A121706(n).
a(n) = - A290844(n-1,n) for n > 1.

A360665 Square array T(n, k) = k*((2*n-1)*k+1)/2 read by rising antidiagonals.

Original entry on oeis.org

0, 0, 0, 0, 1, -1, 0, 2, 3, -3, 0, 3, 7, 6, -6, 0, 4, 11, 15, 10, -10, 0, 5, 15, 24, 26, 15, -15, 0, 6, 19, 33, 42, 40, 21, -21, 0, 7, 23, 42, 58, 65, 57, 28, -28, 0, 8, 27, 51, 74, 90, 93, 77, 36, -36, 0, 9, 31, 60, 90, 115, 129, 126, 100, 45, -45
Offset: 0

Views

Author

Paul Curtz, Mar 17 2023

Keywords

Examples

			By rows:
   0,   0,  -1,  -3,  -6,  -10,  -15,  -21,  -28, ...   = -A161680
   0,   1,   3,   6,  10,   15,   21,   28,   36, ...   =  A000217
   0,   2,   7,  15,  26,   40,   57,   77,  100, ...   =  A005449
   0,   3,  11,  24,  42,   65,   93,  126,  164, ...   =  A005475
   0,   4,  15,  33,  58,   90,  129,  175,  228, ...   =  A022265
   0,   5,  19,  42,  74,  115,  165,  224,  292, ...   =  A022267
   0,   6,  23,  51,  90,  140,  201,  273,  356, ...   =  A022269
   ... .
		

Crossrefs

Programs

  • Mathematica
    T[n_, k_] := ((2*n - 1)*k^2 + k)/2; Table[T[n - k, k], {n, 0, 10}, {k, 0, n}] // Flatten (* Amiram Eldar, Mar 31 2023 *)
  • PARI
    T(n, k) = ((2*n-1)*k^2+k)/2 \\ Thomas Scheuerle, Mar 17 2023

Formula

T(n,k) = T(n,k-1)+k^2.
T(n,n) = A081436(n-1).
T(n,n+1) = A059270(n).
T(n,n+4) = -3*A179297(n+4).
T(n+3,n) = A162254(n).
T(n+5,n) = 3*A101986(n).
From Stefano Spezia, Mar 31 2023: (Start)
O.g.f.: (x*y - y^2 + 2*x*y^2)/((1 - x)^2*(1 - y)^3).
E.g.f.: exp(x+y)*y*(2*x - y + 2*x*y)/2. (End)
Showing 1-3 of 3 results.