18511

Appears in sequences

• a(n) = floor(n*(n-1)*(n-2)/4).at n=43A011886
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 49 ones.at n=0A031817
• Number of triangular partitions of n of order 3.at n=33A084439
• Integers that are Rhonda numbers to base 12.at n=15A100971
• Golden semiprimes: a(n)=p*q and abs(p*phi-q)<1, where phi = golden ratio = (1+sqrt(5))/2.at n=14A108540
• a(n) = floor(n*(n^3-n-3)/(2*(n-1))).at n=31A117561
• O.g.f.: A(x) = Sum_{n>=0} x^n*Product_{k=0..n} (1 + k*(k+1)/2*x).at n=9A124381
• Numbers k such that k^2+1 = 2p,(k+1)^2+1 = 5q, (k+2)^2+1 = 10r where p, q, and r are primes.at n=25A181619
• Number of nondecreasing strings of numbers x(i=1..n) in -3..3 with sum x(i)^3 equal to 0.at n=39A188271
• Numbers n such that 4n+3 is a palindromic prime.at n=41A193419
• Number of days after Mar 01 00 such that the date written in the format DD.MM.YY is palindromic.at n=15A210887
• p*B_(p-1)+1 modulo p^2, where p = prime(n) and B_i denotes the i-th Bernoulli number.at n=39A268000
• Numbers k such that (56*10^k + 367)/9 is prime.at n=17A294231
• Number of compositions of n with no adjacent triples (..., x, y, z, ...) where x < y < z or x > y > z.at n=16A344614
• A sequence of integers from an additive problem with prime numbers.at n=23A348472
• Triangle read by rows: T(n,k) is the number of free polyominoes with n cells whose difference between length and width is k, n >= 1, k >= 0.at n=67A379625