30728

Appears in sequences

• a(n) = A045820(n)/2.at n=19A045822
• a(n) = sigma[k](n) - phi(n)^k - d(n)^k for k=3.at n=29A079539
• Numbers whose square root in base 10 starts with 10 distinct digits.at n=15A113507
• Number of nX(n+3) arrays of permutations of n+3 copies of 0..n-1 with every element equal to or 1 greater than any north, west or northwest neighbors modulo n and the upper left element equal to 0.at n=7A267403
• Numbers n such that Bernoulli number B_{n} has denominator 1410.at n=35A272369
• Let v = list of denominators of Farey series of order n (see A006843); a(n) = sum of products of adjacent terms of v.at n=21A278046
• Decimal representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 201", based on the 5-celled von Neumann neighborhood.at n=34A286670
• Solution of the complementary equation a(n) = 3*a(n-2) + b(n-2), where a(0) = 1, a(1) = 2, b(0) = 3, b(1) = 4, and (a(n)) and (b(n)) are increasing complementary sequences.at n=17A295139
• Number of ways to choose 3 points that form an equilateral triangle from the A000292(n) points in a regular tetrahedral grid of side length n.at n=14A334581
• Integers k such that for all m>k, d(m)/m < d(k)/k where d(j) = Min_{p & q odd primes, 2*j = p+q, p <= q} (q-p)/2.at n=24A335297