28730

Appears in sequences

• a(n) = 2*Catalan(n) - Catalan(n-1).at n=9A000782
• a(n) = Fibonacci(n+2) + prime(n).at n=20A004399
• Number of unrooted triangulations with reflection symmetry of a disk with one internal node and n+3 nodes on the boundary.at n=18A005508
• Coordination sequence for root lattice B_3.at n=38A022145
• Numbers that are the sum of 2 nonzero squares in exactly 6 ways.at n=23A025289
• Numbers that are the sum of 2 nonzero squares in 5 or more ways.at n=33A025296
• Numbers that are the sum of 2 nonzero squares in 6 or more ways.at n=24A025297
• Numbers that are the sum of 2 distinct nonzero squares in exactly 6 ways.at n=23A025307
• Numbers that are the sum of 2 distinct nonzero squares in 5 or more ways.at n=31A025315
• Numbers that are the sum of 2 distinct nonzero squares in 6 or more ways.at n=24A025316
• Numbers k whose decimal representation, read as a base-23 value and divided by k, yields an integer.at n=22A032577
• Sums of distinct powers of 13.at n=20A033049
• Distinct even numbers in writing first numerator and then denominator of each element of the 1/4-Pascal triangle (by row).at n=15A046589
• Square roots of sums of squares of divisors in A046655.at n=15A046656
• a(n) = (7*n+2)*C(n)/(n+2), where C(n) is the n-th Catalan number.at n=8A061557
• Numbers which can be written as b^2*c^2*(b^2+c^2).at n=28A063663
• a(n) = floor( (4/3)*Pi*n^3 ).at n=19A066645
• Numbers k such that core(k) = ceiling(sqrt(k)) where core(k) is the squarefree part of k (the smallest integer such that k*core(k) is a square).at n=12A069187
• a(n) = n^2*(n^2+1).at n=13A071253
• Sum of two powers of 13.at n=12A072390