A279170 - OEIS

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

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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.