22855

Appears in sequences

• Numbers k such that k, k+1, k+2 and k+3 have the same number of divisors.at n=32A006601
• Numbers n such that n*6^n - 1 is prime.at n=18A059675
• a(n) is the largest number such that all of a(n)'s length-n substrings are distinct and divisible by 57.at n=2A093257
• Least k such that decimal representation of k*n contains only digits 0 and 7.at n=33A096686
• O.g.f.: Sum_{n>=0} x^n * (n + x)^n / (1 + n*x)^n.at n=7A230741
• Integers which can be written in exactly three ways as sum of two distinct nonzero pentagonal numbers.at n=23A333013
• a(n) is the least number k such that A349474(k) = A349474(k+1) = n, or -1 if no such k exists.at n=10A349500
• a(n) = Sum_{j=1..n} Sum_{k=1..n} phi(j*k).at n=20A372633