228459

Appears in sequences

• Fermat coefficients.at n=20A000971
• Molien series for 3-D group X1.at n=41A037240
• a(1) = 1, a(2) = 2, next terms up to a(2n-1) are obtained by multiplying previous terms a(n-1) by n+1, a(n-2) by n+2 etc. a(2) by (2n-2) and a(1) by 2n-1. On similar lines a(2n) = 2n*a(2n-2), a(2n+1) = (2n+1)*a(2n-1) and so on.at n=42A109844
• a(1) = 1, a(2) = 2; a(n) = lcm(n, a(n-2)), a(n+1) = lcm((n+1), a(n-3)) and so on until a(2n-1) = lcm(2n-1, a(1)). Then a(2n) = lcm(2n, a(2n-2)) and so on.at n=42A109849
• a(n) = (n-1)*n*(n+1)*(n+2)*(2*n+1)/40.at n=21A112851
• Binomial(prime(n),s)/prime(n) where s is the sum of the decimal digits of n.at n=14A176266
• a(n) = 7*binomial(8*n+7,n)/(8*n+7).at n=5A234466
• Magic sums of 3 X 3 semimagic squares composed of squares of primes.at n=10A269344
• a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/7)} a(7*k) * a(n-1-7*k).at n=41A386396