150150

Appears in sequences

• Degrees of irreducible representations of Fischer group Fi22.at n=23A003913
• a(n) = 35*(n+1)*binomial(n+4, 7)/4.at n=6A027803
• a(n) = 21*(n+1)*binomial(n+4,9).at n=4A027805
• a(1)=1, a(2)=2; thereafter, a(n) is the smallest number m not yet in the sequence such that every prime that divides a(n-1) also divides m.at n=39A060735
• Numbers k such that phi(k) < k/5.at n=17A066765
• Integers which have more than one coprime factorization into nonprime powers which sum to the same number.at n=16A072940
• a(n) = 140*C(2n,n)/(n+4).at n=8A078819
• Integers n for which the ratio phi(n)/pi(n) is smaller than for any subsequent n. Here phi(n) is Euler's totient function and pi(n) is the number of primes that are at most n.at n=25A080289
• Array read by rows: T(n,k) = binomial(n+k-2,k-1)*binomial(2*n-1,n-k).at n=32A091811
• a(n) = binomial(n+6,6)*binomial(n+9,9).at n=4A107421
• Numbers with exactly 6 distinct prime divisors {2,3,5,7,11,13}.at n=4A147573
• Numbers with prime factorization pqrstu^2.at n=15A189985
• Number of (w,x,y,z) with all terms in {1,...,n} and w>=2x and y<=3z.at n=29A212521
• Numbers k such that k+1, 2k+1, 3k+1, 4k+1 are all prime.at n=35A237189
• a(n) gives the denominators for A250031(n) as well as for A250032(n).at n=14A250033
• Number T(n,k) of 2n-length strings of balanced parentheses of exactly k different types that are introduced in ascending order; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=32A253180
• Number of 2n-length strings of balanced parentheses of exactly 4 different types that are introduced in ascending order.at n=3A258392
• Totient superdeficient numbers: numbers n > 1 such that s(n)/n < s(m)/m for all m < n, where s(n) is the sum of iterated phi(n) (A092693).at n=12A291173
• Numbers m that set records for the ratio A045763(n)/n.at n=36A294492
• Numbers k that give record values for s(k)*phi(k)/k^2, where s(k) is the sum of squares of the differences between consecutive totatives of k (A322144).at n=28A322165