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.

A001255 Squares of partition numbers.

Original entry on oeis.org

1, 1, 4, 9, 25, 49, 121, 225, 484, 900, 1764, 3136, 5929, 10201, 18225, 30976, 53361, 88209, 148225, 240100, 393129, 627264, 1004004, 1575025, 2480625, 3833764, 5934096, 9060100, 13823524, 20839225, 31404816, 46812964, 69705801, 102880449, 151536100
Offset: 0

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Author

Keywords

Crossrefs

Programs

Formula

a(n) = A000041(n)^2.
a(n) ~ exp(2*Pi*sqrt(2*n/3)) / (48*n^2). - Vaclav Kotesovec, Dec 01 2015
Sum_{n>=1} 1/a(n) = A200089. - Amiram Eldar, May 01 2021
a(n) = A006907(n) + A051748(n) + A051749(n). - R. J. Mathar, Mar 09 2022
a(n) = [(x*y)^n] Product_{k>=1} 1 / ((1 - x^k) * (1 - y^k)). - Ilya Gutkovskiy, Apr 24 2025

Extensions

Extended by Ray Chandler, Nov 14 2005

A006907 Number of zeros in character table of symmetric group S_n.

Original entry on oeis.org

0, 0, 1, 4, 10, 29, 55, 153, 307, 588, 1018, 2230, 3543, 6878, 11216, 20615, 33355, 57980, 90194, 155176, 239327, 395473, 604113, 970294, 1453749, 2323476, 3425849, 5349414, 7905133, 11963861, 17521274, 26472001, 38054619, 56756488, 81683457, 119005220, 170498286, 247619748
Offset: 1

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Author

Keywords

References

  • J. McKay, personal communication to N. J. A. Sloane, circa 1991.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Programs

  • GAP
    A006907 := n -> Sum(Irr(CharacterTable("Symmetric", n)), chi -> Number(chi, x->x=0)); # Eric M. Schmidt, Jul 13 2012, simplified Jul 26 2012
  • Mathematica
    a[n_] := Count[FiniteGroupData[{"SymmetricGroup", n}, "CharacterTable"], 0, 2]; Array[a, 10] (* Jean-François Alcover, Oct 08 2016 *)

Formula

a(n) + A051748(n) + A051749(n) = A001255(n). - R. J. Mathar, Mar 09 2022

Extensions

More terms from Vladeta Jovovic, May 20 2003
More terms from Eric M. Schmidt, Jul 13 2012
a(36)-a(38) found by Alexander R. Miller (see 2019 reference). - N. J. A. Sloane, Jul 07 2020

A051748 Number of character table entries of the symmetric group S_n which are < 0.

Original entry on oeis.org

0, 1, 2, 7, 13, 34, 72, 137, 249, 524, 953, 1679, 3106, 5270, 9398, 15666, 26284, 43409, 72861, 115940, 189476, 297929, 476904, 743094, 1174624, 1782368, 2787256, 4196505, 6413986, 9645485, 14553197, 21483398, 32243250, 47165359, 69606943
Offset: 1

Views

Author

JOHN MCKAY (mckay(AT)cs.concordia.ca), Dec 08 1999

Keywords

Crossrefs

Programs

Extensions

More terms from Eric M. Schmidt, Jul 14 2012
Showing 1-3 of 3 results.