23870

Appears in sequences

• Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 3,0,2.at n=5A037655
• 5th binomial transform of (0,1,0,2,0,4,0,8,0,16,...).at n=6A081182
• Squarefree oblong (pronic) numbers having an odd number of prime factors.at n=20A098827
• Numbers k such that the central binomial coefficient C(2k,k) is divisible by k^2.at n=37A121943
• Half the number of length n integer sequences with sum zero and sum of squares 7200.at n=3A157592
• a(n) = n*(n+1)*(5*n + 4)/6.at n=30A162147
• a(n) = (2*n^3 + 5*n^2 - 3*n)/2.at n=27A162256
• a(n) = (n^3 + 4*n^2 - n)/2.at n=34A162260
• Diagonal sums of number triangle A186020.at n=9A186022
• Multiples of 682.at n=35A200860
• Numbers k such that 4*5^k + 1 is prime.at n=8A204322
• Number of (w,x,y,z) with all terms in {1,...,n} and w<=2x and y>=3z.at n=21A212515
• Numbers n such that n = x + y, sigma_1(n) = sigma_1(x) + sigma_1(y) and sigma_2(n) = sigma_2(x) + sigma_2(y).at n=14A219033
• a(n) = (4*n+3)*(4*n+2).at n=38A256833
• a(n) = prime(n)*prime(n+1) + prime(n+2).at n=35A292926
• Numbers that occur in range of A324580.at n=48A324541
• Numbers k such that prime(k+1)^prime(k+3) == prime(k) mod prime(k+2).at n=12A335571
• Oblong numbers which are products of five distinct primes.at n=7A359304
• a(n) = Sum_{i+j+k+l=n, i,j,k,l >= 1} sigma(i)*sigma(j)*sigma(k)*sigma(l).at n=11A374977