19747

Appears in sequences

• Numbers k such that k^2 is palindromic in base 6.at n=20A029990
• Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 2,3,1.at n=5A037641
• Numbers which are the sum of two positive cubes and divisible by 31.at n=31A102658
• a(n) = prime(n)_prime(n).at n=33A122622
• a(n) + a(n+1) + a(n+2) = n^3.at n=40A152728
• 7 times octagonal numbers: a(n) = 7*n*(3*n-2).at n=31A153797
• Numbers such that n^2 = 29 mod 1193.at n=33A165989
• Vandermonde sequence using x^2 + xy + y^2 applied to (1,3,5,...,2n-1).at n=2A203514
• Sum_{0<j<k<=n} s(k)-s(j), where s(j)=A002620(j) is the j-th quarter-square.at n=24A206806
• Antidiagonal sums of the convolution array A213841.at n=12A213843
• Numbers of the form 3^j + 8^k, for j and k >= 0.at n=47A226821
• Numbers that are the sum of eight fourth powers in eight or more ways.at n=34A345583
• Numbers that are the sum of eight fourth powers in nine or more ways.at n=13A345584
• Numbers that are the sum of eight fourth powers in ten or more ways.at n=4A345585
• Numbers that are the sum of eight fourth powers in exactly ten ways.at n=4A345842
• Numbers that can be represented in more than one way as p^2+p*q+q^2 with p and q primes, p<=q.at n=18A349987
• a(n) = Sum_{1 <= x_1, x_2, x_3 <= n} gcd(x_1, x_2, n)/gcd(x_1, x_2, x_3, n).at n=23A373061