131054

Appears in sequences

• Eulerian numbers (Euler's triangle: column k=2 of A008292, column k=1 of A173018).at n=17A000295
• Distinct elements occurring in triangle of Eulerian numbers (sorted).at n=24A030196
• a(n) = 2^n - A056045(n).at n=16A056200
• Least k such that k(k+1)(k+2)...(k+n) divides C(2k,k).at n=14A072119
• a(n) = Sum_{k=0..n} (1-(-1)^( floor( (-n-k)/2^k ) )) * 2^(k-1).at n=16A105229
• a(n) = 2^(n+1) - n - 2, or partial sums of main diagonal of array A125127 of k-step Lucas numbers.at n=15A125128
• Expansion of e.g.f. e^(2x)-(1+x)*e^x+x.at n=17A130103
• Number of (w,x,y,z) with all terms in {1,...,n} and |x-y|<|y-z|.at n=23A212681
• Number of odd permutations on {1,2,...,n} with exactly 2 weak excedances.at n=18A293047
• Subsequence of A071395. The extra constraint is m is not a term if m*q/p is abundant where prime p|m and q is the least prime larger than p.at n=13A333967
• Primitive nondeficient numbers satisfying a stronger condition that compares abundancy with related numbers as detailed in the comments.at n=39A352739
• Number of nonisomorphic unordered pairs of involutions on an n-set.at n=30A362649
• G.f. satisfies A(x) = 1 + x^4*A(x)*(1 + x*A(x)).at n=45A365727
• Products of 5 distinct primes that are sandwiched between sphenic numbers.at n=18A376929