25442

Appears in sequences

• Number of proper factorizations of p1^n*p2^2, where p1 and p2 are distinct primes.at n=24A031125
• Expansion of 1 / Product_{k >= 1} (1-q^k)^2*(1-q^(11k))^2.at n=20A032442
• Becomes prime after n iterations of f(x) = sigma(x)-1 (least inverse of A039655).at n=20A039656
• Numbers n for which there are exactly ten k such that n = k + reverse(k).at n=29A072434
• a(n) = 2^(-n)*Sum_{k=0..n} binomial(2*n+1, 2*k+1)*A000364(n-k).at n=5A111196
• The number of unlabeled graphs on n nodes with degree of 1 or 2.at n=32A186417
• The number of 4-alternating permutations of [n].at n=11A250259
• Number of (n+2) X (4+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000001 00000101 or 00000111.at n=18A261707