A118236 Numbers that can be written as sums of at least two distinct but overlapping sets of consecutive numbers.

9, 15, 18, 21, 30, 35, 42, 45, 50, 55, 60, 63, 65, 70, 75, 77, 81, 84, 90, 91, 99, 105, 108, 117, 119, 126, 132, 133, 135, 140, 143, 147, 150, 153, 154, 156, 162, 165, 171, 175, 180, 187, 189, 195, 196, 198, 207, 209, 210, 216, 220, 221, 225, 231, 234, 245, 247

Offset

1,1

Comments

A001227(a(n)) > 2.

Complement of A328369. - Omar E. Pol, Nov 19 2019

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10000

Example

30 = 4+5+(6+7+8) = (6+7+8)+9 with common summands = {6,7,8}, therefore 30 is a term.

Mathematica

Position[#, _?(# > 0 &)][[All, 1]] &@ Array[Count[Tally@ Flatten@ Select[IntegerPartitions[#], Union@ Differences@ # == {-1} &], _?(Last@ # > 1 &)] &, 60] (* Michael De Vlieger, Nov 22 2019 *)

Crossrefs

Cf. A328369.

Sequence in context: A364566 A177733 A207675 * A230306 A070876 A266419

Adjacent sequences: A118233 A118234 A118235 * A118237 A118238 A118239

Keyword

nonn

Author

Reinhard Zumkeller, Apr 18 2006

Status

approved