49105

Appears in sequences

• Number of permutations satisfying -k <= p(i) - i <= r and p(i) - i not in I, i=1..n, with k=1, r=5, I={1,3}.at n=24A079962
• Count of interior bounded regions in a regular 2n-sided polygon dissected by all diagonals parallel to sides.at n=21A165217
• Expansion of -1/((1 - x)*(1 - x^2 + 4*x^3)).at n=21A175714
• Composite squarefree numbers k such that p+1 divides k-1 for any prime p dividing k.at n=9A225711
• Sequence a(n) = (1 + A007805(n))/2, appearing in a certain touching problem for three circles and a chord, together with A007805.at n=4A246641
• Number of n X 4 integer arrays with each element equal to the number of horizontal and antidiagonal neighbors equal to itself.at n=20A266008
• Numbers n with record number of primes p such that n*p is a Lucas-Carmichael number.at n=4A292368
• a(n) is the least integer k such that k/Fibonacci(n) > 1/4.at n=27A293552
• The number of tiles inside a regular n-gon created by diagonals that run from each of the n vertices to the n-2 midpoints of opposite edges.at n=21A320422
• Intersection of A099011 and A327651.at n=28A327652
• NSW pseudoprimes: odd composite numbers k such that A002315((k-1)/2) == 1 (mod k).at n=34A330276
• Odd composite integers m such that U(m)^2 == 1 (mod m) and V(m) == 5 (mod m), where U(m) and V(m) are the m-th generalized Lucas and Pell-Lucas numbers of parameters a=5 and b=-1, respectively.at n=34A337628
• Composite terms in A270951.at n=39A351337
• Numbers k so that the binary expansion of 3^k starts with the binary expansion of k.at n=20A385157