The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A120273 Absolute value of the numerator of Sum[ (-1)^i * i/Prime[i], {i,1,n}]. 1
 1, 1, 13, 29, 731, 4357, 136141, 1497401, 52856987, 698076077, 49526267143, 574253997269, 72925181864501, 1123720869207397, 143426539122302791, 2236629947933814637, 422054527184135696827, 8864360144543549996813 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS G. C. Greubel, Table of n, a(n) for n = 1..300 FORMULA a(n) = Abs[ numerator[ Sum[ (-1)^i*i/Prime[i], {i,1,n}]]]. MATHEMATICA Abs[Numerator[Table[Sum[(-1)^i*i/Prime[i], {i, 1, n}], {n, 1, 20}]]] PROG (PARI) for(n=1, 20, print1(numerator(abs(sum(k=1, n, (-1)^k*k/prime(k)))), ", ")) \\ G. C. Greubel, Aug 23 2018 (MAGMA) [Numerator(Abs((&+[(-1)^k*k/NthPrime(k): k in [0..n]]))): n in [1..20]]; // G. C. Greubel, Aug 23 2018 CROSSREFS Sequence in context: A317897 A195878 A013545 * A104817 A048450 A216193 Adjacent sequences:  A120270 A120271 A120272 * A120274 A120275 A120276 KEYWORD frac,nonn AUTHOR Alexander Adamchuk, Jul 01 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 August 1 22:36 EDT 2021. Contains 346408 sequences. (Running on oeis4.)