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A106481 An Euler phi transform of 1/(1-x^2). 1
0, 1, 1, 3, 3, 7, 5, 13, 9, 19, 13, 29, 17, 41, 23, 49, 31, 65, 37, 83, 45, 95, 55, 117, 63, 137, 75, 155, 87, 183, 95, 213, 111, 233, 127, 257, 139, 293, 157, 317, 173, 357, 185, 399, 205, 423, 227, 469, 243, 511, 263, 543, 287, 595, 305, 635, 329, 671, 357, 729 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

a(2n)=A049690(n). a(2n+1)=A099957(n).

LINKS

Table of n, a(n) for n=0..59.

FORMULA

a(n)=sum{k=0..n, phi(n-k+1)*mod(k, 2)}

Euler transform of period 7 sequence [3,-2,-1,-1,-2,3,0,...].

CROSSREFS

Sequence in context: A070801 A114753 A079316 * A106477 A098043 A324866

Adjacent sequences:  A106478 A106479 A106480 * A106482 A106483 A106484

KEYWORD

easy,nonn

AUTHOR

Paul Barry, May 03 2005

STATUS

approved

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Last modified August 5 08:46 EDT 2021. Contains 346464 sequences. (Running on oeis4.)