23734

Appears in sequences

• Numbers k such that 100k+1, 100k+3, 100k+7, 100k+9 are all primes.at n=33A064687
• Integer part of Gauss's Arithmetic-Geometric Mean M(2,n^4).at n=20A127765
• a(n) = Sum_{d|n} d*binomial(n/d+d-2,d-1).at n=53A157020
• Number of n X 3 0..1 arrays with every element equal to 0, 1, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=27A302510
• a(n) = Sum_{k=1..n} phi(k)*phi(k+1)*phi(k+2), where phi(k) = A000010(k) is Euler's totient function.at n=24A335131
• a(n) = A349976(n, n-1) for n >= 1 and a(0) = 0.at n=17A349972
• a(n) is the number of 5 element sets of distinct integer-sided trapezoids whose base angles are 60 degrees that fill an equilateral triangular grid of side n units formed by directly binary space partitioning 3-trapezoid sets without forming 4-trapezoid sets.at n=39A391203