27553

Appears in sequences

• Base-9 palindromes that start with 4.at n=36A043031
• a(n) is the number of n-tosses having a run of 5 or more heads for a fair coin (i.e., probability is a(n)/2^n).at n=16A050233
• Semiprimes in A056106.at n=31A113524
• E.g.f. A(x) = exp(x+x^2+x^3+x^4+x^5).at n=7A193931
• Centered 32-gonal numbers.at n=41A195315
• Number of length 2+2 0..n arrays with some pair in every consecutive three terms totalling exactly n.at n=27A245871
• Triangle read by rows: T(n,k) is the number of nilpotent subpermutations on an n-set, each of nilpotency index less than or equal to k.at n=33A261764
• Number of Dyck paths of semilength n such that each level with peaks has exactly two peaks.at n=14A287843
• Square array A(n,k), n >= 0, k >= 1, read by antidiagonals downwards, where column k is the expansion of e.g.f. exp(Sum_{j=1..k} x^j).at n=73A293669
• Number of defective (binary) heaps on n elements from the set {0,1} with exactly one defect.at n=21A372628
• Squarefree semiprimes k such that k+1 is the product of three distinct primes and k+2 is the product of four distinct primes.at n=41A376352
• Numbers m that divide the alternating sum Sum_{k=1..m} (-1)^(k+1) * usigma(k).at n=13A379924