A309106 Triangular array T(m,n): number of sequences of n residues modulo m such that no nonempty subsequence sums to zero, for m>=1, n=0..m-1.

1, 1, 1, 1, 2, 2, 1, 3, 6, 2, 1, 4, 12, 16, 4, 1, 5, 20, 44, 10, 2, 1, 6, 30, 96, 90, 36, 6, 1, 7, 42, 174, 240, 84, 28, 4, 1, 8, 56, 288, 690, 336, 168, 48, 6, 1, 9, 72, 440, 1344, 984, 336, 144, 36, 4, 1, 10, 90, 640, 2590, 3060, 2100, 1200, 450, 100, 10

Offset

1,5

Comments

T(m,n)=0 if n>=m.

Links

Table of n, a(n) for n=1..66.

Brendan McKay et al., probability of zero subset sum, MathOverflow, 2013.

Crossrefs

Columns: A000012 (n=0), A000027 (n=1), A002378 (n=2).

Diagonals: A000010 (n=m-1), A062955 (n=m-2, starting with m=4).

Sequence in context: A340107 A125231 A117919 * A160014 A068956 A124842

Adjacent sequences: A309103 A309104 A309105 * A309107 A309108 A309109

Keyword

nonn,tabl

Author

Max Alekseyev, Jul 12 2019

Status

approved