27864

Appears in sequences

• Numbers that are the products of distinct substrings (>1) of themselves and do not end in 0.at n=32A059470
• Engel expansion of Sum_{k>=0} 1/(10 + k)^k.at n=16A063193
• Sum of n-th antidiagonal of array in A081998.at n=22A082001
• a(n) = sigma((4^n - 1)/3), where sigma(n) is the sum of positive divisors of n.at n=7A102359
• Numbers that have exactly eight prime factors counted with multiplicity (A046310) whose digit reversal is different and also has 8 prime factors (with multiplicity).at n=2A109028
• Number of n X n binary arrays, symmetric under horizontal and vertical reflection, with every 1 adjacent to at least one other 1 both bishopwise and rookwise but with no three 1s in a row bishopwise or rookwise.at n=12A144238
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, 0, 1), (0, -1, 1), (0, 1, -1), (1, 1, 0)}.at n=9A148986
• Number of n X 4 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.at n=15A207020
• Area A of the cyclic quadrilaterals PQRS with PQ>=QR>=RS>=SP, such that A, the sides, the radius of the circumcircle and the two diagonals are integers.at n=43A219225
• Numbers n for which number of iterations to reach the largest equals number of iterations to reach 1 from the largest in Collatz (3x+1) trajectory of n.at n=28A224303
• a(n) = number of primes less than the square root of the (2^n)-th prime.at n=32A249058
• Triangle read by rows: T(n,k) is the number of n X n binary matrices with k=0..n^2 ones forming a polyomino, under action of dihedral group of the square D_4.at n=53A331462
• Fourier coefficients of the modular form (1/t_{3A}^2) * F_{3A}^12.at n=16A341558
• Indices of 0 in A348295: numbers m such that Sum_{k=1..m} (-1)^(floor(k*(sqrt(2)-1))) = Sum_{k=1..m} (-1)^A097508(k) = 0.at n=37A348299
• Sum of the divisors of A001045(n) (Jacobsthal numbers).at n=15A366772
• a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/3)} binomial(n-1,3*k) * a(3*k) * a(n-1-3*k).at n=11A386202