27728

Appears in sequences

• Solutions of a fifth-order probability difference equation.at n=20A001949
• Define the generalized Pisot sequence T(a(0),a(1)) by: a(n+2) is the greatest integer such that a(n+2)/a(n+1) < a(n+1)/a(n). This is T(16,32).at n=11A018923
• Numbers k such that k!!!!!! + 1 is prime.at n=44A085150
• Numbers k such that 4^k + 3 is prime.at n=29A089437
• Number of subsets of {1,2,3,...,n} whose sum is a square integer (including the empty subset).at n=19A126024
• Difference between 2^n and the largest factorial <= 2^n.at n=15A135996
• Nonprimes in the triangle A141020.at n=29A141031
• 7-step Fibonacci sequence starting with (0,0,1,0,0,0,0).at n=22A251713
• Numbers k such that (115*10^k - 7)/9 is prime.at n=17A295083
• Number of pairs (lambda,mu) of partitions lambda of n and mu of floor(n/2) with mu <= lambda (by diagram containment).at n=22A303851
• Number of pairs (lambda,mu) of partitions lambda of n and mu of ceiling(n/2) with mu <= lambda (by diagram containment).at n=22A303852
• Number of pairs (lambda,mu) of partitions lambda of 2n and mu of n with mu <= lambda (by diagram containment).at n=11A303861
• Starts of runs of 4 consecutive positive negabinary-Niven numbers (A331728).at n=8A331824
• a(n) is the number of interior points in the n-th figure shown in A255011 (meaning the figure with 4n points on the perimeter), counted with multiplicity.at n=7A334697
• Number of compositions of 2n into n parts where differences between neighboring parts are in {-1,1}.at n=28A364529
• Number of integer compositions of n whose leaders of maximal strictly increasing runs sum to 2.at n=41A374705
• a(n) = pos(M(n)), where M(n) is the n X n matrix with numbers 1, 2, ..., n^2 in order across rows, and pos(M(n)) is the positive part of the determinant of M(n); see A380661.at n=3A381723