99690
domain: N
Appears in sequences
- Suppose you take the ten digits 0..9, arrange them in any order and then either concatenate adjacent ones or separate them with a plus or minus sign, e.g., 98-76+5-4-32+10 or 9-8-765+3041-2. The first expression totals to "1", the second example totals to "2275". This sequence lists the positive integers that cannot be expressed in this way.at n=5A108224
- a(n) is the number of ways to select 3 distinct points forming a triangle of unsigned area = n from a square of grid points with side length n, divided by 4.at n=25A320542
- Triangle T(n,k) defined by Sum_{k=1..n} T(n,k)*u^k*x^n/n! = exp(Sum_{n>0} u*d(n)*x^n/n!), where d(n) is the number of divisors of n.at n=47A338870