20864

Appears in sequences

• Number of abstract simplicial 2-complexes on {1,2,3,...,n+4} which triangulate a Moebius band in such a way that all vertices lie on the boundary and are traversed in the order 1,2,3,... as one goes around the boundary.at n=5A007817
• a(n) = n*(2*n^2 - 3*n + 4)/3.at n=32A037235
• Numbers k such that 7*10^k + R_k + 2 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=5A103050
• Maxima in A163169.at n=44A163172
• Number of (n+1) X 3 binary arrays with no 2 X 2 subblock sum equal to any horizontal or vertical neighbor 2 X 2 subblock sum.at n=7A185791
• Number of (n+1) X 9 binary arrays with no 2 X 2 subblock sum equal to any horizontal or vertical neighbor 2 X 2 subblock sum.at n=1A185797
• T(n,k) = Number of (n+1) X (k+1) binary arrays with no 2 X 2 subblock sum equal to any horizontal or vertical neighbor 2 X 2 subblock sum.at n=37A185798
• T(n,k) = Number of (n+1) X (k+1) binary arrays with no 2 X 2 subblock sum equal to any horizontal or vertical neighbor 2 X 2 subblock sum.at n=43A185798
• Number of cyclotomic cosets of 9 mod 10^n.at n=36A220020
• Partitions with parts repeated at most twice and repetition only allowed if first part has an even index (first index = 1).at n=57A227135
• Number of (n+1) X (6+1) 0..2 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally.at n=6A253467
• Number of (n+1) X (7+1) 0..2 arrays with every 2 X 2 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally, vertically, diagonally and antidiagonally.at n=5A253469
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 145", based on the 5-celled von Neumann neighborhood.at n=31A270288
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 841", based on the 5-celled von Neumann neighborhood.at n=26A273685
• Numbers k such that (71*10^k - 287)/9 is prime.at n=21A286936
• Primitive practical numbers of the form 2^i * prime(k).at n=36A308710
• a(n) is the smallest abundant number of the form 2^e * prime(n).at n=36A341361
• a(n) = A376877(n) / p where p is the largest prime factor of A376877(n).at n=39A376874
• Numbers which can be written in precisely one way as sum of a subset of their proper divisors and that have exactly one subset of their divisors such that the complement has the same sum.at n=51A378530