21257

Appears in sequences

• n^3+Largest square, (Largest square <= n^3).at n=22A176580
• a(n) = (27^n - 2^n)/25.at n=4A180844
• Number of special sums of integer partitions of n.at n=26A304796
• Number of compositions (ordered partitions) of n into at most 6 prime parts (counting 1 as a prime).at n=45A347761
• Numbers k of the form (x + y)*(x^2 + y^2) such that (x + y) and (x^2 + y^2) are primes.at n=33A349202
• Positive integers that cannot be written as a sum of a practical number and a heptagonal number.at n=68A373444
• Odd semiprimes k = p*q such that k = A325820(p,q), with p, q primes > 3, and A325820 is the carryless base-3 multiplication.at n=48A391331