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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A342128 Table read by antidiagonals upwards: T(n,k) is the number of n-colorings of the vertices of the k-dimensional hypercube such that no two adjacent vertices have the same color. n >= 0, k >=0.

Original entry on oeis.org

0, 1, 0, 2, 0, 0, 3, 2, 0, 0, 4, 6, 2, 0, 0, 5, 12, 18, 2, 0, 0, 6, 20, 84, 114, 2, 0, 0, 7, 30, 260, 2652, 2970, 2, 0, 0, 8, 42, 630, 29660, 1321860, 1185282, 2, 0, 0, 9, 56, 1302, 198030, 187430900, 130253748108, 100301050602, 2, 0, 0, 10, 72, 2408, 932862, 10199069190, 2157531034816940
Offset: 0

Views

Author

Peter Kagey, Feb 28 2021

Keywords

Examples

			Table begins:
  n\k|  0   1     2         3                4                              5
  ---+-----------------------------------------------------------------------
   0 |  0   0     0         0                0                              0
   1 |  1   0     0         0                0                              0
   2 |  2   2     2         2                2                              2
   3 |  3   6    18       114             2970                        1185282
   4 |  4  12    84      2652          1321860                   130253748108
   5 |  5  20   260     29660        187430900               2157531034816940
   6 |  6  30   630    198030      10199069190            7905235551766437150
   7 |  7  42  1302    932862     269591166222         7365707045872206479742
   8 |  8  56  2408   3440024    4221404762120      2337101560809838105414712
   9 |  9  72  4104  10599192   44876701584360    327425229254999498091796728
  10 | 10  90  6570  28478970  355148098691850  24489214732779742874109277530
		

Crossrefs

Columns and rows: A002378 (k=1), A091940 (k=2), A140986 (k=3), A158348 (k=4), A380589 (k=5), A307334 (n=3).
Cf. A334278, A342088 (analogous for cross-polytope).

Formula

T(n,k) = Sum_{i=0..2^k} A334278(k,i)*n^i.

A100606 a(n) = n^4 + n^3 + n.

Original entry on oeis.org

0, 3, 26, 111, 324, 755, 1518, 2751, 4616, 7299, 11010, 15983, 22476, 30771, 41174, 54015, 69648, 88451, 110826, 137199, 168020, 203763, 244926, 292031, 345624, 406275, 474578, 551151, 636636, 731699, 837030, 953343, 1081376, 1221891, 1375674, 1543535, 1726308
Offset: 0

Views

Author

Douglas Winston (douglas.winston(AT)srupc.com), Nov 30 2004

Keywords

Crossrefs

Programs

Formula

a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5); a(0)=0, a(1)=3, a(2)=26, a(3)=111, a(4)=324. - Harvey P. Dale, Apr 25 2015
From Elmo R. Oliveira, Aug 29 2025: (Start)
G.f.: x*(3 + 11*x + 11*x^2 - x^3)/(1-x)^5.
E.g.f.: x*(3 + 10*x + 7*x^2 + x^3)*exp(x). (End)

A123658 a(n) = 1 + n^4 + n^6 + n^9 + n^10.

Original entry on oeis.org

5, 1617, 79543, 1315073, 11735001, 70591825, 322948907, 1208225793, 3874742893, 11001010001, 28297158495, 67080151297, 148467846593, 309923269713, 615105191251, 1168247947265, 2134605998037, 3768860634193, 6453801131783, 10752064160001, 17474246985385
Offset: 1

Views

Author

Jonathan Vos Post, Oct 04 2006

Keywords

Examples

			a(40) = 1+40^(A001358(1))+40^(A001358(2))+40^(A001358(3))+40^(A001358(4)) = 1+40^4+40^6+40^9+40^10 = 10747908098560001.
		

Crossrefs

Programs

  • Magma
    [1+n^4+n^6+n^9+n^10: n in [0..50]]; // G. C. Greubel, Oct 17 2017
  • Mathematica
    Table[1+n^4+n^6+n^9+n^10, {n,1,50}] (* G. C. Greubel, Oct 17 2017 *)
    LinearRecurrence[{11,-55,165,-330,462,-462,330,-165,55,-11,1},{5,1617,79543,1315073,11735001,70591825,322948907,1208225793,3874742893,11001010001,28297158495},30] (* Harvey P. Dale, Jul 11 2025 *)
  • PARI
    a(n)=1+n^4+n^6+n^9+n^10 \\ Charles R Greathouse IV, Oct 07 2015
    

Formula

a(n) = 1 + n^4 + n^6 + n^9 + n^10.
G.f.: x*(x^10 -8*x^9 +615*x^8 +33654*x^7 +381288*x^6 +1242534*x^5 +1378908*x^4 +528210*x^3 +62031*x^2 +1562*x +5)/(1-x)^11. - Colin Barker, May 27 2012

A131473 a(n) = n^6 - n.

Original entry on oeis.org

0, 0, 62, 726, 4092, 15620, 46650, 117642, 262136, 531432, 999990, 1771550, 2985972, 4826796, 7529522, 11390610, 16777200, 24137552, 34012206, 47045862, 63999980, 85766100, 113379882, 148035866, 191102952, 244140600, 308915750
Offset: 0

Views

Author

Mohammad K. Azarian, Jul 27 2007

Keywords

Crossrefs

Programs

A277443 Square array A(n,k) (n>=1, k>=1) read by antidiagonals: A(n,k) is the number of n-colorings of the prism graph Y_k on 2k vertices.

Original entry on oeis.org

0, 0, 0, 0, 2, 0, 0, 0, 18, 0, 0, 2, 12, 84, 0, 0, 0, 114, 264, 260, 0, 0, 2, 180, 2652, 1920, 630, 0, 0, 0, 858, 16080, 29660, 8520, 1302, 0, 0, 2, 1932, 119844, 367080, 198030, 28140, 2408, 0, 0, 0, 7074, 816984, 4843460, 4067280, 932862, 76272, 4104, 0, 0, 2, 18660, 5784492, 62682480, 85847910, 28576380, 3440024, 179424, 6570, 0
Offset: 1

Views

Author

Jeremy Tan, Oct 15 2016

Keywords

Comments

Y_1 contains a loop, so has no colorings with any number of colors. Y_2 is the cycle graph C_4 with two double edges; these two graphs are therefore equivalent with respect to number of colorings.

Examples

			Square array A(n,k) begins:
  0,   0,    0,      0,       0,        0,          0, ...
  0,   2,    0,      2,       0,        2,          0, ...
  0,  18,   12,    114,     180,      858,       1932, ...
  0,  84,  264,   2652,   16080,   119844,     816984, ...
  0, 260, 1920,  29660,  367080,  4843460,   62682480, ...
  0, 630, 8520, 198030, 4067280, 85847910, 1800687000, ...
		

Crossrefs

Cf. A277444 (colorings of Möbius ladders), A182406 (square grid graphs).
Columns k=1,2 are A000004 and A091940.
Rows n=1,2 are A000004 and A010673.

Formula

A(n,k) = (n^2-3n+3)^k+(n-1)((3-n)^k+(1-n)^k)+n^2-3n+1.
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