A092289 Number of triangles of partition numbers with the n-partition number as largest side.

1, 2, 4, 5, 7, 8, 10, 10, 12, 14, 16, 17, 18, 19, 22, 23, 24, 25, 26, 27, 29, 31, 32, 34, 36, 37, 38, 39, 41, 42, 44, 45, 47, 48, 49, 50, 53, 54, 55, 56, 57, 58, 61, 62, 65, 66, 67, 68, 69, 71, 72, 73, 74, 77, 78, 79, 81, 83, 84, 85, 86, 87, 89, 91, 93, 94, 95, 96, 97, 98

Offset

1,2

Comments

a(n) = #{(i,j): 1<=i<=j<=n and P(n)<=P(i)+P(j)}, P=A000041.

Links

Table of n, a(n) for n=1..70.

Example

a(10)=14: P(10)=42 and
42<=P(10)+P(10)=42+42,42<=P(10)+P(9)=42+30, 42<=P(10)+P(8)=42+22,
42<=P(10)+P(7)=42+15, 42<=P(10)+P(6)=42+11, 42<=P(10)+P(5)=42+7,
42<=P(10)+P(4)=42+5, 42<=P(10)+P(3)=42+3, 42<=P(10)+P(2)=42+2,
42<=P(10)+P(1)=42+1, 42<=P(9)+P(9)=30+30, 42<=P(9)+P(8)=30+22,
42<=P(9)+P(7)=30+15 and 42<=P(8)+P(8)=22+22.

Crossrefs

Sequence in context: A005839 A254792 A062102 * A079358 A184014 A183856

Adjacent sequences: A092286 A092287 A092288 * A092290 A092291 A092292

Keyword

nonn

Author

Reinhard Zumkeller, Feb 06 2004

Status

approved