27274

Appears in sequences

• Number of 3-edge-connected rooted cubic maps with 2n nodes and a distinguished Hamiltonian cycle.at n=7A000264
• Number of compositions of n such that the greatest part occurs with even multiplicity.at n=17A105204
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 1, -1), (-1, 1, 0), (1, 0, -1), (1, 0, 1)}.at n=9A149152
• Numbers k such that k^2 + 1 == 0 (mod 41^2).at n=32A157116
• Number of subsets A of {0,1,...,n-1} with |A+A| > |A-A|.at n=25A222807
• Records in A341755 (= length of chain of (k,k+1) sharing a digit with k+(k+1), starting at n).at n=13A341756
• For 1<=x<=n, 1<=y<=n with gcd(x,y)=1, write 1 = gcd(x,y) = u*x+v*y with u,v minimal; a(n) = m^2*s, where s is the population variance of the values of |v| and m is the number of such values.at n=12A345695
• a(n) = (3/2)*A019565((2n-1)^2) - A019565(A001065((2n-1)^2)), where A019565 is the base-2 exp-function, and A001065 is the sum of proper divisors of n.at n=23A379501
• Positions of powerful terms among the numbers satisfying Euler's condition for odd perfect numbers (A228058).at n=9A388279