A279170 a(n) is the smallest among the natural numbers m with the property that there exists a non-constant quadratic map S^n -> S^m from the n-dimensional sphere to the m-dimensional sphere.

1, 2, 2, 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8, 8, 16, 16, 16, 16, 16, 16, 16, 16, 16, 24, 24, 24, 24, 24, 24, 24, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 40, 40, 40, 40, 40, 40, 48, 48, 48, 48, 48, 48, 48, 48, 48, 56, 56, 56, 56, 56, 56, 56, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 72, 72, 72, 72, 80, 80, 80, 80, 80, 80, 80, 80, 80, 88, 88, 88, 88, 88, 88, 88, 96, 96, 96, 96, 96

Offset

1,2

Comments

Coincides with A053644 until n=24.

Links

Table of n, a(n) for n=1..100.

P. Yiu, Quadratic Forms between Euclidean Spheres, Manuscripta Math. 83, pp. 171-181 (1994).

Formula

Uniquely determined by the following: a(2^t + m) = 2^t if 0 <= m < A003484(2^t); a(2^t + m) = 2^t + a(m) if A003484(2^t) <= m < 2^t.

Crossrefs

A003484 used in the definition. Cf. A053644.

Sequence in context: A367026 A028397 A053644 * A292254 A292942 A039593

Adjacent sequences: A279167 A279168 A279169 * A279171 A279172 A279173

Keyword

nonn

Author

Mamuka Jibladze, Dec 07 2016

Status

approved