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A140427
Arises in relating doubly-even error-correcting codes, graphs and irreducible representations of N-extended supersymmetry.
1
0, 0, 0, 0, 1, 1, 2, 3, 4, 4, 4, 4, 5, 5, 6, 7, 8, 8, 8, 8, 9, 9, 10, 11, 12, 12, 12, 12, 13, 13, 14, 15, 16, 16, 16, 16, 17, 17, 18, 19, 20, 20, 20, 20, 21, 21, 22, 23, 24, 24, 24, 24, 25, 25, 26, 27, 28, 28, 28, 28, 29, 29, 30
OFFSET
0,7
COMMENTS
Conjecture: essentially partial sums of A169675 (verified for n <= 10000). - Sean A. Irvine, Jul 19 2022
LINKS
C. F. Doran, M. G. Faux, S. J. Gates Jr, T. Hubsch, K. M. Iga and G. D. Landweber, Relating Doubly-Even Error-Correcting Codes, Graphs and Irreducible Representations of N-Extended Supersymmetry, arXiv:0806.0051 [hep-th], 2008. See formula (13) on page 6.
FORMULA
a(n) = 0 for 0 <= n < 4, a(n) = floor(((n-4)^2)/4)+1 for n = 4, 5, 6, 7, and a(n) = a(n-8) + 4 for n>7.
G.f.: x^4*(x^4+x^3+x^2+1) / ((x-1)^2*(x+1)*(x^2+1)*(x^4+1)). - Colin Barker, May 04 2013
MAPLE
A140427 := proc(n) local l: l:=[0, 0, 0, 0, 1, 1, 2, 3]: if(n<=7)then return l[n+1]:else return l[(n mod 8) + 1] + 4*floor(n/8): fi: end:
seq(A140427(n), n=0..62); # Nathaniel Johnston, Apr 26 2011
MATHEMATICA
a[n_] := Module[{L = {0, 0, 0, 0, 1, 1, 2, 3}}, If[n <= 7, L[[n + 1]], L[[Mod[n, 8] + 1]] + 4*Floor[n/8]]];
Table[a[n], {n, 0, 62}] (* Jean-François Alcover, Nov 28 2017, from Maple *)
CROSSREFS
Sequence in context: A287635 A189660 A194167 * A194816 A178770 A072229
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Jun 18 2008
STATUS
approved