cp's OEIS Frontend

This is sequence repeat(0, S, reverse(S)), with S := Sequence(a(n), n = 1..18). [0, ordered(S)] is A010398. - Wolfdieter Lang, Jun 24 2019

Positive numbers represented by the indefinite quadratic form 3x^2+xy-3y^2, of discriminant 37. - N. J. A. Sloane, Jun 05 2014 [Typo corrected by Klaus Purath, Apr 24 2023]

Also positive numbers of the form x^2 + (2m+1)xy + (m^2+m-9)y^2, m, x, y integers. All squares as well as the products of any terms belong to the sequence. Thus, this set of terms is closed under multiplication. - Klaus Purath, Apr 24 2023

A positive integer k belongs to the sequence if and only if k (modulo 37) is a term of A010398 and, moreover, in the case that prime factors p of k are terms of A038914, they occur only with even exponents. Or, more briefly, any positive integer is a term of this sequence if none of its divisors is an odd power of primes from A038914. For these primes also p (modulo 37) = {2, 5, 6, 8, 13, ...} = A028750 applies. - Klaus Purath, May 12 2023