27567

Appears in sequences

• G.f. satisfies: A(x) = 1 / Product_{n>=1} (1 + x^n*A(x)) * (1 + x^n/A(x)) * (1-x^n).at n=12A216878
• Number T(n,k) of colored integer partitions of n using all colors of a k-set such that all parts have different color patterns and a pattern for part i has i colors in (weakly) increasing order; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=42A327116
• The sum of the numbers on straight lines of incrementing length n when drawn over numbers of the square spiral, where each line contains numbers which sum to the minimum possible value, and each number on the spiral can only be in one line. If two or more lines exist with the same sum the one containing the smallest number is chosen.at n=32A340974
• Indices of the prime factors of Fermat numbers in the sequence of primes.at n=8A343557
• Indices where prime(n) first appears in A373902.at n=39A371618
• Expansion of e.g.f. 1/(1 - 3 * arcsinh(x)).at n=5A385368