249401880
domain: N
Appears in sequences
- a(n) = 4^n - C(4,3)*3^n + C(4,2)*2^n - C(4,1).at n=13A000919
- Palindromes using exactly four different symbols.at n=26A056455
- Palindromes using exactly four different symbols.at n=27A056455
- Number of periodic palindromes using exactly four different symbols.at n=26A056490
- Triangle read by rows: T(n,k) = Sum_{j=0..2k} (-1)^j * binomial(2k,j) * (2+k-j)^(2n).at n=30A390029