44222

Appears in sequences

• Number of step shifted (decimated) sequences using exactly two different symbols.at n=17A056376
• Slowest increasing and self-describing sequence: first 2 digits are prime digits, followed by 3 composite digits, then 4 prime digits, then 6 composite digits, then 8 prime, then 2 composite, then 2 prime, etc.at n=34A105808
• Digital sum of the Fermat number 2^(2^n) + 1.at n=15A108301
• Semiprimes (A001358) made of nontrivial runs of identical digits.at n=30A116063
• Expansion of Product_{k>=1} ((1 + x^(2*k - 1))/(1 - x^(2*k - 1)))^(k^2).at n=16A294755
• a(1) = 0 and a(n+1) > a(n) is the smallest integer such that a(n+1)^2-a(n)^2 is triangular.at n=25A358416
• Numbers whose prime factorization (prime factors and exponents) contains the digits 1 and 2 at least once, but no other digits.at n=33A364484
• For a positive number k, let L(k) denote the list consisting of k followed by the prime factors of k, with repetition, in nondecreasing order; sequence gives composite k such that the digits of L(k) are in nonincreasing order.at n=31A372034