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.

A083064 Square number array T(n,k) = (k*(k+2)^n+1)/(k+1) read by antidiagonals.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 3, 5, 1, 1, 4, 11, 14, 1, 1, 5, 19, 43, 41, 1, 1, 6, 29, 94, 171, 122, 1, 1, 7, 41, 173, 469, 683, 365, 1, 1, 8, 55, 286, 1037, 2344, 2731, 1094, 1, 1, 9, 71, 439, 2001, 6221, 11719, 10923, 3281, 1, 1, 10, 89, 638, 3511, 14006, 37325, 58594, 43691, 9842, 1
Offset: 0

Views

Author

Paul Barry, Apr 21 2003

Keywords

Examples

			Rows begin:
1  1   1    1     1      1       1        1         1 ...
1  2   5   14    41    122     365     1094      3281 ...  A007051
1  3  11   43   171    683    2731    10923     43691 ...  A007583
1  4  19   94   469   2344   11719    58594    292969 ...  A083065
1  5  29  173  1037   6221   37325   223949   1343693 ...  A083066
1  6  41  286  2001  14006   98041   686286   4804001 ...  A083067
1  7  55  439  3511  28087  224695  1797559  14380471 ...  A083068
1  8  71  638  5741  51668  465011  4185098  37665881 ...  A187709
1  9  89  889  8889  88889  888889  8888889  88888889 ...  A059482
1 10 109 1198 13177 144946 1594405 17538454 192922993 ...  A199760, etc.
Column 2: A000027;
column 3: A028387;
column 4: A083074;
column 5: A125082;
column 6: A125083.
Diagonals:
1,  2,  11,   94,  1037,  14006, ... A083069;
1,  3,  19,  173,  2001,  28087, ... A083071;
1,  4,  29,  286,  3511,  51668, ... A083072;
1,  5,  41,  439,  5741,  88889, ... A083073;
1,  5,  43,  469,  6221,  98041, ... A083070;
1, 14, 171, 2344, 37325, 686286, ... A191690.
Triangle begins:
1;
1, 1;
1, 2, 1;
1, 3, 5, 1;
1, 4, 11, 14, 1;
1, 5, 19, 43, 41, 1;
1, 6, 29, 94, 171, 122, 1; etc.
		

Crossrefs

Extensions

Edited by Bruno Berselli, Jun 21 2013

A117667 a(n) = n^n-n^(n-1)-n^(n-2)-n^(n-3)-...-n^3-n^2-n.

Original entry on oeis.org

1, 2, 15, 172, 2345, 37326, 686287, 14380472, 338992929, 8888888890, 256780503551, 8105545862052, 277635514376233, 10257237069745862, 406615755353655135, 17216961135462248176, 775537745518440716417
Offset: 1

Views

Author

Luc Stevens (lms022(AT)yahoo.com), Apr 11 2006

Keywords

Examples

			a(3) = 3^3-3^2-3 = 27-9-3 = 15.
		

Crossrefs

Cf. A000312 (n^n), A023037 (1+n+n^2+...n^(n-1)),

Programs

  • Maple
    a:=n->n^n-sum(n^j,j=1..n-1): seq(a(n),n=1..19); # Emeric Deutsch, Apr 16 2006
  • Mathematica
    s[n_] := Sum[n^i, {i, 1, n - 1}]; Table[n^n - s[n], {n, 17}] (* Carlos Eduardo Olivieri, Apr 14 2015 *)
    f[n_] := ((n - 2) n^n + n)/(n - 1); f[1] = 1; Array[f, 18] (* Robert G. Wilson v, Apr 15 2015 *)

Formula

a(n) = A000312(n) - A023037(n) + 1. - Michel Marcus, Apr 14 2015
A191690(n)+1. - Robert G. Wilson v, Apr 16 2015

A191624 Largest prime factor of n^n - n^(n-1) - n^(n-2) - ... - n^2 - n - 1.

Original entry on oeis.org

7, 19, 293, 1493, 179, 1091, 10593529, 379721, 165664841, 66987982331, 240717199, 28048051, 133933781, 25506609089573701, 107140256350247, 793435901761, 268232479553269300213, 4075297, 3063504618316968426599, 1372263056872621, 7514001866134191512025247
Offset: 3

Views

Author

Juri-Stepan Gerasimov, Jun 12 2011

Keywords

Crossrefs

Programs

  • Maple
    A006530 := proc(n) max ( numtheory[factorset](n) ) ;end proc:
    A191690 := proc(n) n^n-add( n^j,j=0..n-1) ;end proc:
    A191624 := proc(n) A006530(A191690(n)) ; end proc:
    seq(A191624(n),n=3..15) ; # R. J. Mathar, Jun 23 2011
  • Mathematica
    Table[With[{s=n^Range[0,n]},FactorInteger[Last[s]-Total[Most[s]]][[-1,1]]],{n,3,20}] (* Harvey P. Dale, Feb 02 2015 *)
  • PARI
    a(n) = if(n==0, return(1)); vecmax(factor(n^n - (n^n-1)/(n-1))[,1]); \\ Daniel Suteu, Jun 09 2022

Formula

a(n) = A006530(A191690(n)).

Extensions

More terms from Harvey P. Dale, Feb 02 2015
Showing 1-3 of 3 results.