28645

Appears in sequences

• a(n) = ceiling(n*phi^15), where phi is the golden ratio, A001622.at n=21A004970
• Strong pseudoprimes to base 72.at n=18A020298
• Strong pseudoprimes to base 84.at n=13A020310
• Strong pseudoprimes to base 98.at n=26A020324
• Odd 10-gonal (or decagonal) numbers.at n=42A028993
• Numbers whose base-5 representation contains exactly three 0's and three 4's.at n=24A045217
• Number of ascents of length at least 2 in all skew Dyck paths of semilength n.at n=37A128751
• Antidiagonal sums of triangular array T defined in A014430: T(j,k) = binomial(j+1, k) - 1 for 1 <= k <= j.at n=19A129696
• a(1) = b(1) = 0; for n > 1, b(n) = b(n-1) + n-1 + a(n-1) and a(n) = a(n-1) + n-1 + b(n).at n=10A152891
• Numbers k such that 2^(2k-1) == 2 (mod 2k) and such that 2^(k-1) != 1 (mod k).at n=41A176033
• Number of n X n symmetric 0..7 arrays with no element equal to the difference mod 8 of any two of its horizontal and vertical neighbors.at n=2A193812
• a(n) = n*(4*n - 3)*(16*n^2 - 12*n - 3).at n=5A264895
• Number of nX7 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 2 or 3 neighboring 1s.at n=2A297636
• T(n,k)=Number of nXk 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 2 or 3 neighboring 1s.at n=38A297637
• Number of 3Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 2 or 3 neighboring 1s.at n=6A297639
• Numbers of the form p*q*r where p, q, r are distinct primes congruent to 1 mod 4 such that Legendre(p/q) = Legendre(p/r) = Legendre(q/r) = -1.at n=26A323271
• Composite numbers k of the form 4u+1 for which the odd part of phi(k) divides k-1.at n=20A339870
• Odd composite numbers k such that A053575(k) [the odd part of phi] divides k-1.at n=51A339880