500000000000
domain: N
Appears in sequences
- Denominator of sum of -12th powers of divisors of n.at n=9A017688
- Expansion of (1-5*x)/(1-10*x).at n=12A093143
- a(n)=Product{k=0..n, 1+4^A010060(k)}/2.at n=23A101654
- Period of powers of 3 mod 10^n.at n=12A216099
- Period of powers of 11 mod 10^n.at n=11A216156
- Period of powers of 7 mod 10^n.at n=13A216164
- Let x(1)x(2)... x(2q) denote the decimal expansion of a number n with an even number of digits. The sequence lists the numbers n such that (10^q-a)*(10^q-b) = n where a is the number having the digits x(1)x(2)...x(q) and b is the number having the digits x(q+1)x(q+2)...x(2q).at n=27A245587
- a(n) = 2^((n-1) mod 2)*5*10^floor((n-1)/2).at n=23A268100
- Number of odd digits necessary to write all nonnegative n-digit integers.at n=10A359271