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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A218795 Numbers that can be written in more than 1 way as p^2 + 3pq + q^2 with primes p < q.

Original entry on oeis.org

671, 1595, 3629, 3839, 4661, 4895, 5771, 8459, 11495, 13079, 17951, 19829, 21251, 22895, 23411, 34751, 40211, 40799, 43829, 45791, 46031, 47795, 49001, 53009, 57209, 57959, 60119, 60491, 64829, 67595, 70661, 78755, 83201, 89249, 98879
Offset: 1

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Author

M. F. Hasler, Nov 05 2012

Keywords

Comments

According to the comment in A218771, there is no prime in this sequence.
The subsequence of terms allowing more than 2 decompositions of the given form starts 136895, 266741, 716441, 902495, 941501, 963281, 1003295, 1033241, 1236539, 1245431, 1439345, 1463495, 1692995, 2300045, 2430461, 3016145, 3238289,...

Examples

			a(1) = 671 = p^2+3pq+q^2 for (p,q)=(2,23) and (5,19), is the least term to allow more than 1 decomposition of the given form.

Crossrefs

Cf. A218794 for PARI code and further discussion.
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