21175

Appears in sequences

• Transformation of A036490: 5^a*7^b*11^c -> 5^a*7^floor((b+2)/2)*11^c.at n=46A036491
• a(n) = (n+1)^2 * (n+2)^2 * (2*n+3) / 12.at n=9A108674
• Numbers k such that the number of prime divisors of the k-th Catalan number (counted with multiplicity) divides k.at n=30A121612
• Numbers n such that A242719(n) = (prime(n))^2+1 and A242720(n) - A242719(n) = 2*(prime(n)+1).at n=25A246748
• Numbers n which appear at least twice in A037278(n), concatenation of their divisors written in base 10.at n=30A248323
• a(n) = n*(n+1)*(13*n+2)/6.at n=21A257093
• Number of elements of order n in simple Higman-Sims group HS.at n=1A284915
• Square root of the prime factor form (A276086) of the primorial base expansion, computed for such numbers for which it is a square.at n=58A328834
• Terms of A349937 that are not divisible by 3: numbers k > 1 not divisible by 2 or 3 such that A309906(k-1) < A309906(k) > A309906(k+1).at n=9A349941
• Inverse Moebius transform of A000056.at n=29A350156
• a(n) = n*(1 - (-1)^n - 2*(3 + (-1)^n)*n^2 + 2*n^4)/384.at n=21A350689
• Numbers that can be written as the product of two divisors greater than 1 such that the number is contained in the string concatenation of the divisors.at n=32A355790
• a(n) = numerator((n!)^2/(2*(n-2)!*n^n)).at n=10A370200
• Expansion of e.g.f. exp( x^3/6 + x^4/24 ).at n=12A390845