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A120107 a(n)=sum{lcm(1,..,2(n-k)+2)/lcm(1,..,2k+2), k=0..floor(n/2)}. 1
1, 6, 31, 425, 1331, 14084, 182533, 390855, 6192220, 117429752, 136000866, 2700408581, 13835919839, 42477252404, 1171690228133, 72397239805085, 84274330442804, 86644937313210, 2686078920033439, 3119346038772923 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Diagonal sums of number triangle A120101.

CROSSREFS

Sequence in context: A121754 A200775 A144576 * A015462 A006115 A144780

Adjacent sequences:  A120104 A120105 A120106 * A120108 A120109 A120110

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Jun 09 2006

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Last modified February 15 08:20 EST 2012. Contains 205729 sequences.