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A177733 Integers that can be expressed as the sum of two or more positive consecutive numbers (the largest being even) AND also as the sum of two or more positive consecutive numbers (the largest being odd). 0
9, 15, 18, 21, 27, 30, 33, 35, 36, 39, 42, 45, 49, 51, 54, 55, 57, 60, 63, 66, 69, 70, 72, 75, 77, 78, 81, 84, 87, 90, 91, 93, 95, 98, 99, 102, 105, 108, 110, 111, 114, 115, 117, 119, 120, 121, 123, 126, 129, 132, 133, 135, 138, 140, 141, 143, 144, 147, 150, 153, 154 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Intersection of A177732 and A177731.

LINKS

Table of n, a(n) for n=1..61.

EXAMPLE

9 is in the sequence because 2+3+4=9=4+5.

15 is in the sequence because 7+8=15=1+2+3+4+5,..

MATHEMATICA

z=200; lst1={}; Do[c=a; Do[c+=b; If[c<=2*z, AppendTo[lst1, c]], {b, a-1, 1, -1}], {a, 1, z, 2}]; Union@lst1; z=200; lst2={}; Do[c=a; Do[c+=b; If[c<=2*z, AppendTo[lst2, c]], {b, a-1, 1, -1}], {a, 2, z, 2}]; Intersection[lst1, lst2]

CROSSREFS

Cf. A000217, A177713.

Sequence in context: A105441 A325164 A093642 * A207675 A118236 A230306

Adjacent sequences:  A177730 A177731 A177732 * A177734 A177735 A177736

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, May 12 2010

STATUS

approved

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Last modified October 23 14:42 EDT 2021. Contains 348214 sequences. (Running on oeis4.)