90900

Appears in sequences

• a(n) = n^2*(n^2 + 1)*(n-1).at n=10A037250
• Euler's totient of numbers containing in their decimal representation only the digits 0 and 1.at n=32A077811
• Numbers whose set of base 10 digits is {0,9}.at n=20A097256
• Numbers k which are concatenations k=x//y such that x^2 + y^2 is a multiple of k.at n=31A162463
• Numbers such that each digit is the sum of two or more other digits.at n=34A203591
• Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 502", based on the 5-celled von Neumann neighborhood.at n=8A272578
• 8-digit numbers (padded with leading zeros where necessary) in which the sum of the number consisting of the first four digits and the number consisting of the last four digits equals the number consisting of the middle four digits.at n=18A293686
• Numbers m such that the largest digit in the decimal expansion of 1/m is 1.at n=21A333402
• a(n) = phi(10^n+1), where phi is Euler's totient function (A000010).at n=5A366669