A276207 a(0) = a(1) = 0. For n>1 a(n) is the smallest nonnegative integer such that there is no arithmetic progression m_1,m_2,...,m_i,n (2<=i<n) such that a(m_1)+a(m_2)+...+a(m_i) = a(n).

0, 0, 1, 0, 0, 2, 4, 1, 1, 0, 0, 5, 0, 0, 3, 7, 2, 3, 2, 4, 1, 1, 12, 1, 5, 1, 1, 0, 0, 13, 0, 0, 10, 9, 6, 7, 0, 0, 18, 0, 0, 15, 4, 14, 7, 6, 8, 2, 6, 3, 16, 3, 3, 2, 3, 7, 1, 10, 25, 8, 5, 1, 1, 1, 4, 14, 27, 4, 1, 1, 10, 2, 2, 6, 1, 26, 8, 1, 19, 1, 1, 0, 0, 13, 0, 0, 7, 24, 2, 19, 0, 0, 34, 0, 0, 29, 32, 32, 5, 15, 21, 14, 15, 6, 6, 24, 13, 39, 0, 0, 24, 0

Offset

0,6

Comments

The distribution of zeros is the same as in A276204.

Links

Michal Urbanski, Table of n, a(n) for n = 0..49999

Example

For n = 5 we have that:
a(5)>0, because a(3)+a(4)=0 and 3,4,5 is an arithmetic progression
a(5)>1, because a(2)+a(3)+a(4)=1 and 2,3,4,5 is an arithmetic progression
there is no such arithmetic progression m_1,m_2,...,m_i,5 that a(m_1)+a(m_2)+...+a(m_i)=2, so a(5) = 2.

Crossrefs

Cf. A276204 (length 3), A276205 (length 4), A276206 (length 5).

Sequence in context: A094344 A211183 A137391 * A248672 A276631 A059817

Adjacent sequences: A276204 A276205 A276206 * A276208 A276209 A276210

Keyword

nonn

Author

Michal Urbanski, Aug 24 2016

Status

approved