21996

Appears in sequences

• Tribonacci numbers that start with first three squares.at n=15A086192
• Numbers that have exactly six prime factors counted with multiplicity (A046306) whose digit reversal is different and also has 6 prime factors (with multiplicity).at n=34A109026
• Numbers k such that 7^k + 2 is semiprime.at n=22A119720
• Augmentation of the triangular array P given by p(n,k)=k! for 0<=k<=n. See Comments.at n=51A193092
• a(n) = (n-4)*(n+1)*(n+3)/6.at n=47A275874
• p-INVERT of (1,1,1,1,1,...), where p(S) = (1 - S^3)^3.at n=13A291143
• a(n) = Sum_{1 <= j <= n/2, gcd(j,n)=1} j^3.at n=38A295575
• Numbers k such that k divides sum of k-th twin prime pair.at n=34A335303
• a(n) is the smallest positive number that is the sum of no fewer than n distinct repdigits.at n=5A336759
• Least b > 1 such that (b^(prime(n)^2) - 1)/(b^prime(n) - 1) is prime.at n=51A353101
• Number of integer partitions of n where the parts do not have the same median as the distinct parts.at n=38A360244