A379346 Number of integers of the form k^2 + 1 whose greatest prime factor is A002313(n), the n-th prime not congruent to 3 mod 4.

1, 3, 5, 6, 7, 10, 9, 16, 17, 20, 26, 36, 36, 40, 46, 47, 56, 67, 73, 86, 97, 107

Offset

1,2

Comments

See A223702 for additional information.

Links

Table of n, a(n) for n=1..22.

Florian Luca, Primitive divisors of Lucas sequences and prime factors of x^2 + 1 and x^4 + 1, Acta Academiae Paedagogicae Agriensis, Sectio Mathematicae 31 (2004), pp. 19-24.

Filip Najman, Smooth values of some quadratic polynomials, Glasnik Matematicki Series III 45 (2010), pp. 347-355.

Crossrefs

Row lengths of A223702.

First differences of A285283.

Cf. A002313, A177979, A185389.

Sequence in context: A163621 A124194 A359506 * A055597 A053048 A154663

Adjacent sequences: A379343 A379344 A379345 * A379347 A379348 A379349

Keyword

nonn,more

Author

Andrew Howroyd, Dec 22 2024

Status

approved