28080

Appears in sequences

• Theta series of E_6 lattice.at n=20A004007
• Theta series of {E_6}* lattice.at n=44A005129
• a(n) = floor(n*(n-1)*(n-2)*(n-3)/15).at n=27A011925
• Numbers k that divide the (left) concatenation of all numbers <= k written in base 19 (most significant digit on left).at n=45A029488
• Multiplicity of highest weight (or singular) vectors associated with character chi_121 of Monster module.at n=39A034509
• Denominators of continued fraction convergents to sqrt(77).at n=11A041137
• Numbers having four 6's in base 8.at n=24A043448
• Number of nonnegative solutions of x1^2 + x2^2 + ... + x10^2 = n.at n=23A045852
• Number of double-free subsets of {1, 2, ..., n}.at n=18A050291
• T(n,3), array T as in A054126.at n=9A054129
• a(n) = Product_{k|n} (n+1-k).at n=15A056819
• Number of 6-ary Lyndon words of length n with trace 0 and subtrace 5 over Z_6.at n=8A074427
• Number of 6-ary Lyndon words of length n with trace 3 and subtrace 5 over Z_6.at n=8A074445
• Sum of divisors of numbers containing in their decimal representation only the digits 0 and 1.at n=23A077810
• Products x*y*z arising from A102505.at n=31A102793
• a(n) = (3*n+1)*(5*n+1).at n=43A144459
• a(n)=1*(n+2)!-2*(n+1)!-3*n!.at n=6A152456
• Number of nondecreasing integer sequences of length 12 with sum zero and sum of absolute values 2n.at n=15A158146
• a(n) = binomial(n+1,2)*6^2.at n=39A162940
• Difference A063990(2n)-A063990(2n-1) between amicable numbers.at n=22A178542