81257

Appears in sequences

• Numbers k such that the determinant of the Vandermonde matrix of their digits is equal to sigma(k), the sum of divisors of k.at n=11A307586
• Squarefree terms of A129802 whose prime factors are neither elite (A102742) nor anti-elite (A128852), where A129802 is the possible bases for Pepin's primality test for Fermat numbers.at n=15A372895