19640

Appears in sequences

• Least term in period of continued fraction for sqrt(n) is 7.at n=28A031431
• Solution to the Dancing School Problem with 11 girls and n+11 boys: f(11,n).at n=3A079916
• Solution to the Dancing School Problem with n girls and n+3 boys: f(n,3).at n=10A079922
• Alternating sum of the squares of the first n Fibonacci numbers with index divisible by 3.at n=4A156090
• a(n) = 49*n^2 + 2*n.at n=19A157365
• Arises in classification of base sequences.at n=30A173061
• Number of (n+4) X 10 0..1 matrices with each 5 X 5 subblock idempotent.at n=13A224688
• Number of (n+1) X (1+1) 0..1 arrays with no element having a strict majority of its horizontal, vertical, diagonal and antidiagonal neighbors equal to one.at n=9A231799
• Number of compositions of n with exactly seven occurrences of the largest part.at n=17A243742
• Expansion of e.g.f. sec(log(1 + x)) + tan(log(1 + x)).at n=9A306336
• Number of (undirected) cycles in the graph C_3 X P_n.at n=7A339136
• a(n) is the least k such that a k-gon is the first polygon where an agreement of the areas of k-gons inscribed and circumscribed to a unit circle agree with the true value of Pi when truncated to n digits.at n=7A391013