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A295220 a(n) = Sum_{i=1..floor(n/2)} floor((n+i)/i) - floor((n-i-1)/i). 1
0, 3, 3, 6, 5, 9, 7, 11, 10, 13, 11, 17, 13, 17, 17, 20, 17, 23, 19, 25, 23, 25, 23, 31, 26, 29, 29, 33, 29, 37, 31, 37, 35, 37, 37, 44, 37, 41, 41, 47, 41, 49, 43, 49, 49, 49, 47, 57, 50, 55, 53, 57, 53, 61, 57, 63, 59, 61, 59, 71, 61, 65, 67, 70, 67, 73 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
It appears that the odd prime numbers are fixed points of the sequence.
LINKS
MAPLE
A295220:=n->add(floor((n+i)/i)-floor((n-i-1)/i), i=1..floor(n/2)): seq(A295220(n), n=1..120); # Wesley Ivan Hurt, Nov 29 2017
MATHEMATICA
Table[Sum[Floor[(n + i)/i] - Floor[(n - i - 1)/i], {i, Floor[n/2]}], {n, 60}]
CROSSREFS
Cf. A000040.
Sequence in context: A071047 A265008 A165606 * A280167 A257143 A080512
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Nov 17 2017
STATUS
approved

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Last modified March 29 10:22 EDT 2024. Contains 371268 sequences. (Running on oeis4.)