21282
domain: N
Appears in sequences
- Fibonacci sequence beginning 2, 7.at n=18A022113
- Numbers which are the sum of their proper divisors containing the digit 4.at n=32A059463
- Maximal value of Sum_{i=1..n} (p(i) - p(i+1))^2, where p(n+1) = p(1), as p ranges over all permutations of {1, 2, ..., n}.at n=39A064842
- a(0)=2, a(1)=5, a(n+2) = a(n+1) + (-1)^n a(n).at n=36A095795
- a(0)=2, a(1)=5, a(n+2) = a(n+1) + (-1)^n a(n).at n=39A095795
- Row sums of the triangle A097883.at n=34A098404
- Indices k such that A020507(k)=Phi[k](-8) is prime, where Phi is a cyclotomic polynomial.at n=34A138922
- Number of ways to write n as an ordered sum of 9 nonzero triangular numbers.at n=33A340954