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A127012 a(0)=1. a(n) = the numerator of the sum of the reciprocals of the earlier terms of the sequence which divide n. 1
1, 1, 2, 2, 3, 2, 23, 2, 4, 7, 4, 2, 16, 2, 36, 7, 89, 2, 35, 2, 13, 55, 6, 47, 7, 2, 171, 7, 53, 2, 15, 2, 129, 7, 15, 96, 307, 2, 8, 94, 69, 2, 68, 2, 19, 37, 208, 95, 163, 19, 9, 7, 249, 107, 173, 111, 587, 139, 9, 2, 319, 2, 10, 215, 171, 27, 21, 2, 749, 55, 402, 2, 99, 2, 853, 37 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..75.

EXAMPLE

The sequence's terms, among terms a(0) through a(8), which divide 9 are a(0)=1, a(1)=1 and a(4)=3. So a(9) is the numerator of 1 +1 +1/3 = 7/3, which is 7.

MATHEMATICA

f[l_List] := Sum[1/l[[k]], {k, Length[l]}]; g[l_List] := Block[{n = Length[l]}, Append[l, Numerator@f[Select[l, Mod[n, # ] == 0 &]]]]; Nest[g, {1}, 75] (* Ray Chandler, Jan 04 2007 *)

CROSSREFS

Cf. A127011.

Sequence in context: A329350 A283450 A297935 * A125503 A127009 A181313

Adjacent sequences:  A127009 A127010 A127011 * A127013 A127014 A127015

KEYWORD

nonn

AUTHOR

Leroy Quet, Jan 02 2007

EXTENSIONS

Extended by Ray Chandler, Jan 04 2007

STATUS

approved

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Last modified June 29 15:34 EDT 2022. Contains 354913 sequences. (Running on oeis4.)