18744

Appears in sequences

• Denominator of B(4n+2)/(8n+4) where B(m) are the Bernoulli numbers.at n=16A043304
• Largest integer m such that m divides (sigma_(2n+1)(2k-1)-sigma(2k-1)) for all k>=1.at n=34A081863
• Least positive k such that k * [RSA-200]^n - 1 is prime, where RSA-200 is the 200 decimal digit RSA challenge number A391940(15).at n=39A108375
• Positive integers i for which A112049(i) == 8.at n=20A112068
• Number of 4-almost primes less than or equal to 10^n.at n=5A114106
• Triangle read by rows: T(k,n) is number of numbers <= 10^n that are products of k primes.at n=34A126280
• Number of permutations in S_n avoiding {bar 4}1253 (i.e., every occurrence of 1253 is contained in an occurrence of a 41253).at n=8A137540
• Largest number k such that the reduced totient function psi(k) = A002174(n).at n=28A143407
• Coefficients of the sixth-order mock theta function phi_{-}(q).at n=29A153251
• Maximal length of chain-addition sequence mod 10 with window of size n.at n=6A181190
• Numbers n for which A222085(n)=A222085(n+1).at n=18A222088
• Numbers k that divide the base-5 reversal of k.at n=13A222816
• Number of n X n 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.at n=2A233233
• Number of n X 3 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.at n=2A233234
• T(n,k)=Number of nXk 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.at n=12A233239
• Number of 3Xn 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.at n=2A233241
• Number of Sidon subsets of {1,...,n} of size 5.at n=25A241689
• Terms of A143407, sorted.at n=38A270564
• a(n) = A000203(A276086(n)).at n=55A324653
• Indices of unique values in A329152.at n=20A333268