18497

Appears in sequences

• a(n) = 10*n^2 + 7.at n=43A061722
• a(n) = 16*n^2 + 1.at n=33A108211
• Central coefficients of number triangle A113582.at n=16A154323
• a(n) = 64*n^2 + 1.at n=17A158686
• Number of binary strings of length n with equal numbers of 00100 and 10011 substrings.at n=15A164241
• a(0) = 0 and a(n) = (4*n^3 - 12*n^2 + 20*n - 9)/3 for n >= 1.at n=25A174794
• Numbers of the form n^2 + 1 without prime divisors of the form a^2 + 1.at n=12A217279
• Consider a number of k digits n = d_(k)*10^(k-1) + d_(k-1)*10^(k-2) + ... + d_(2)*10 + d_(1). Sequence lists the numbers n such that n' = Sum_{i=1..k-1}{Sum_{j=1..i}{d_(j)*10^(j-1)}}', where n' is the arithmetic derivative of n (see example below).at n=38A244078
• Expansion of f(x^2)^2 / f(-x) in powers of x where f() is a Ramanujan theta function.at n=36A260163
• Number of sets of exactly n positive integers <= n+6 having a square element sum.at n=25A281969
• a(n) = Sum_{k=1..n} (k/gcd(n, k))^3.at n=16A343513