|
Search: id:A126577
|
|
|
| A126577 |
|
a(n) = numerator of the sum of reciprocals of the terms in n-th row of triangle A077581. |
|
+0
2
|
|
| 1, 4, 7, 176, 9, 133542, 103, 91072, 99527, 131023748, 7591, 300996993816, 88001, 1403843964196, 44094737, 10686452707072, 825533, 368070779365071896502, 2895701, 8653175044141052500, 81659533540907, 3080940707518158404
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
LINKS
|
Leroy Quet, Home Page (listed in lieu of email address)
|
|
EXAMPLE
|
Row 4 of triangle A077581 is (1,3,5,7).
So a(4) is the numerator of 1/1 +1/3 +1/5 + 1/7 = 176/105.
|
|
MATHEMATICA
|
row[n_] := Take[Select[Range[n^2], GCD[ #, n] == 1 &], n]; Table[Numerator[Plus @@ (1/# &) /@ row[n]], {n, 23}] (*Chandler*)
|
|
CROSSREFS
|
Cf. A077581, A126578.
Sequence in context: A156474 A136276 A024054 this_sequence A073164 A134900 A028583
Adjacent sequences: A126574 A126575 A126576 this_sequence A126578 A126579 A126580
|
|
KEYWORD
|
frac,nonn
|
|
AUTHOR
|
Leroy Quet Dec 28 2006
|
|
EXTENSIONS
|
Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Dec 29 2006
|
|
|
Search completed in 0.002 seconds
|
