30280

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 87.at n=34A031585
• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 87.at n=1A031765
• Number of orbits of length n under the map whose periodic points are counted by A001641.at n=23A060166
• Number of parts in all partitions of n in which no part occurs more than 3 times.at n=33A117148
• Product plus sum of five consecutive nonnegative numbers.at n=6A173044
• Demi-tribonacci numbers (rounding down): a(0)=a(1)=0, a(2)=2; a(n) = floor( (a(n-1)+a(n-2)+a(n-3))/2 ).at n=53A180234
• Number of decompositions of highly composite numbers (A002182) into unordered sums of two primes.at n=40A228943
• Expansion of Product_{k>=1} ((1+x^k)/(1-x^k))^(2*k-1).at n=11A261452
• Partial sums of A206032 (Product_{d|n} sigma(d)).at n=14A280085
• Coefficients in q-expansion of (E_2*E_4 - E_6)^2/(300*(E_6^2-E_4^3)), where E_2, E_4, E_6 are the Eisenstein series shown in A006352, A004009, A013973, respectively.at n=4A281373
• Numbers k such that Bernoulli number B_{k} has denominator 13530.at n=20A295587
• Number of 6Xn 0..1 arrays with every element equal to 0, 1, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=7A303318
• Coefficients of a family of orthogonal polynomials. Triangle read by rows, T(n, k) for 0 <= k <= n.at n=23A322944
• Column 2 of triangle in A288187.at n=13A333279
• a(n) is the determinant of the 2 X 2 matrix whose entries (when read by rows) are the n-th primes congruent to 1, 3, 5, 7 mod 8 respectively.at n=15A337145
• Numbers k such that A322582(k) <= A276086(k) <= A348507(k).at n=47A392602