This site is supported by donations to The OEIS Foundation.

 Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A118063 Denominator of Sum_{i=1..n} 1/(t(i)^t(i)) where t(i) = i-th 3-almost prime. 1
 16777216, 4458050224128, 1259085058409489202413568, 15738563230118615030169600000000000000000000, 46496637333593157266125580467610571799579852800000000000000000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS 3-almost prime analog of A076265. (Semiprime analog of A076265 is A118056.) Fractions are 1/16777216, 265721/4458050224128, 75047458863267833/1259085058409489202413568, 938093235790847912650094635296999121 / 15738563230118615030169600000000000000000000, 2771420766426289313598405374054613260285749630619149892803 / 46496637333593157266125580467610571799579852800000000000000000000. LINKS FORMULA a(n) = Denominator of Sum_{i=1..n} 1/(3almostprime(i)^3almostprime(i)). a(n) = Denominator of Sum_{i=1..n} 1/(A014612(i)^A014612(i)). a(n) = Denominator of Sum_{i=1..n} 1/A114967(n). EXAMPLE a(2) = 4458050224128 because (1/A014612(1)^A014612(1)) + (1/A014612(2)^A014612(2))= (1/(8^8)) + (1/(12^12)) = (1/16777216) + (1/8916100448256) = 265721/4458050224128. CROSSREFS Numerators = A118062. Cf. A001358, A014612, A051674, A114850, A114967, A117579, A118056. Sequence in context: A010812 A016968 A017040 * A017124 A114967 A017220 Adjacent sequences:  A118060 A118061 A118062 * A118064 A118065 A118066 KEYWORD easy,frac,nonn AUTHOR Jonathan Vos Post, Apr 11 2006 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 17 14:50 EST 2018. Contains 318201 sequences. (Running on oeis4.)