18072

Appears in sequences

• a(n) = a(n-1) + a(n-1-(number of odd terms so far)).at n=37A007604
• exp(arctanh(x)*arcsinh(x)) = 1+2/2!*x^2+16/4!*x^4+398/6!*x^6+18072/8!*x^8...at n=4A012752
• Same rule as Aitken triangle (A011971) except a(0,0)=0, a(1,0)=1.at n=47A046936
• Numbers k such that k^2 contains exactly 9 different digits.at n=31A054037
• Number of singular points on n-th order Chmutov surface.at n=35A057870
• Numbers whose square is a zeroless pandigital number (i.e., use the digits 1 through 9 once).at n=6A071519
• a(n) = p(n)*p(n+2)-p(n+1), where p(n) is the n-th prime.at n=31A152530
• Triangle read by rows: T(n, m) = binomial(n, m)* Sum_{k=0..m} binomial(n, k) for 0 <= m <= n.at n=52A167024
• Numbers n such that n contains exactly 5 digits, all distinct, and n^2 contains exactly 9 distinct digits.at n=11A204691
• Total sum of parts of multiplicity 9 in all partitions of n.at n=42A222737
• a(n) is a refactorable number and the sum of all refactorable numbers <= a(n) is also a refactorable number.at n=34A235177
• Number of compositions of n with exactly 3 transitions between different parts.at n=15A244715
• Numbers whose square contains all of the digits 1 through 9.at n=6A294661
• a(n) is the number of n-digit proper prime powers.at n=10A303220
• Number of subsets of {2..n} such that the product of the elements is a decimal palindrome.at n=46A339508
• Irregular triangle read by rows in which T(n,k) is the number of stable matchings in the stable marriage problem with n men and n women such that there exists a stable matching with an egalitarian cost of k.at n=17A344692
• Numbers k such that any two consecutive decimal digits of k^2 differ by 1 after arranging the digits in decreasing order.at n=39A370362