818520
domain: N
Appears in sequences
- a(n) = 4^n - C(4,3)*3^n + C(4,2)*2^n - C(4,1).at n=9A000919
- Triangle of numbers T(n,k) = k!*Stirling2(n,k) read by rows (n >= 1, 1 <= k <= n).at n=48A019538
- Palindromes using exactly four different symbols.at n=18A056455
- Palindromes using exactly four different symbols.at n=19A056455
- Number of primitive (aperiodic) palindromes using exactly four different symbols.at n=18A056465
- Number of periodic palindromes using exactly four different symbols.at n=18A056490
- Number of primitive (period n) periodic palindromes using exactly four different symbols.at n=18A056500
- T(n, k) = Sum_{j=0..n-k} (-1)^j*binomial(n - k + 1, j)*(n - k + 1 - j)^n. Triangle read by rows, T(n, k) for 1 <= k <= n.at n=51A090582
- Triangle read by rows: T(n,k) = Sum_{j=0..2k} (-1)^j * binomial(2k,j) * (2+k-j)^(2n).at n=17A390029