77805

Appears in sequences

• a(n) is the number of Dyck paths of semilength n+6 having its first peak at height n+1.at n=18A005557
• Numbers k such that the k-th triangular number contains each of the 10 decimal digits exactly once.at n=21A115939
• Odd numbers k such that k and phi(k) have the same number of divisors.at n=5A116518
• a(n) = n*(n + 1)*(n + 2)*(3*n + 17)/24.at n=26A241765
• Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 579", based on the 5-celled von Neumann neighborhood.at n=17A283089
• Coefficients in the expansion of 1/([r]-[2*r]*x+[3*r]*x^2-...); [ ]=floor, r=sqrt(e).at n=19A288235
• Coefficients in the expansion of 1/([r]-[2*r]*x+[3*r]*x^2-...); [ ]=floor, r=-4/5+sqrt(6).at n=19A288236
• Triangle read by rows: T(n,k) is the number of simple series-parallel matroids on [n] with rank k, 1 <= k <= n.at n=41A361355
• Nondeficient numbers k for which A324644(k)/A324198(k) = 2.at n=1A387165
• Odd numbers k for which A000005(2*k) >= A017665(2*k), where A000005 is the number of divisors function, and A017665 is the numerator of the abundancy ratio, sigma(k)/k.at n=10A388277
• Odd spoof k-perfect numbers of order <= 10.at n=6A389834