22217

Appears in sequences

• Super-4 Numbers (4 * n^4 contains substring '4444' in its decimal expansion).at n=17A032744
• Least inverse of A048182.at n=31A048183
• Number of primitive (aperiodic) step shifted (decimated) sequence structures using a maximum of three different symbols.at n=12A056402
• Total sum of squares of number of distinct parts in all partitions of n.at n=23A135348
• a(n) is the smallest natural number we cannot obtain from n, n+1, n+2, n+3, n+4, n+5, n+6, n+7 and the operators +, -, *, /, using each number only once.at n=30A143192
• a(n) = 2*n*(1 + n + n^2 + n^3) - 3.at n=10A155121
• a(n) = 42*n^2 - 1.at n=22A158626
• Numbers n such that n'' = n'+1 where n' and n'' are respectively the first and the second arithmetic derivative of n (A003415).at n=6A189639
• For k in {2,3,...,9} define a sequence as follows: a(0)=0; for n>=0, a(n+1)=a(n)+1, unless a(n) ends in k, in which case a(n+1) is obtained by replacing the last digit of a(n) with the digit(s) of k^2. This is k(4).at n=33A237341
• Triangle read by rows: T(n,k) = t(n-k, k); t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 9*x + 1.at n=16A257608
• Triangle read by rows: T(n,k) = t(n-k, k); t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 9*x + 1.at n=19A257608
• Numbers k for which sigma(k) = k + k'', where k'' is the second derivative of k (A068346).at n=7A348426