A265359 Spiralwise distance to the nearest inner neighbor in Ulam-style square-spirals using zero-based indexing: a(0) = 0, for n >= 1, a(n) = n - A265409(n).

0, 1, 2, 3, 4, 5, 6, 7, 7, 8, 9, 9, 10, 11, 11, 11, 12, 13, 13, 13, 14, 15, 15, 15, 15, 16, 17, 17, 17, 17, 18, 19, 19, 19, 19, 19, 20, 21, 21, 21, 21, 21, 22, 23, 23, 23, 23, 23, 23, 24, 25, 25, 25, 25, 25, 25, 26, 27, 27, 27, 27, 27, 27, 27, 28, 29, 29, 29, 29, 29, 29, 29, 30, 31, 31, 31, 31, 31, 31, 31, 31, 32

Offset: 0

Author

Antti Karttunen, Dec 16 2015

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A000267, A002620, A240025, A265409.

Formula

a(0) = 0, for n >= 1, a(n) = n - A265409(n).

If n <= 7, then a(n) = n, otherwise a(n) = a(n-1) + A240025(n) + A240025(n-1).