A161689 Intersection of A151740 and A151741.

49, 99, 153, 161, 171, 175, 185, 189, 221, 231, 235, 243, 247, 265, 285, 289, 319, 329, 341, 351, 369, 375, 391, 405, 429, 435, 441, 469, 473, 495, 507, 517, 531, 535, 545, 549, 581, 589, 603, 609, 639, 645, 651, 657, 667, 671, 679, 689, 711, 715, 725, 729

Offset

1,1

Comments

Composite numbers that are sum of two and three consecutive composite numbers. Provably only odd integers.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

49=24+25=15+16+18
99=49+50=32+33+34
153=76+77=50+51+52.

Mathematica

Module[{c=Select[Range[800], CompositeQ], s2, s3}, s2=Total/@Partition[c, 2, 1]; s3=Total/@Partition[c, 3, 1]; Intersection[c, s2, s3]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 27 2019 *)

Crossrefs

A151740, A151741, A151745.

Sequence in context: A260009 A114013 A235578 * A354342 A230653 A019547

Adjacent sequences: A161686 A161687 A161688 * A161690 A161691 A161692

Keyword

nonn

Author

Zak Seidov, Jun 17 2009

Status

approved