The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A293457 Primes that divide the numerator of the sum of the reciprocals of all smaller primes. 3
 2, 5, 19, 47, 79, 109, 3667387 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Exhaustive search finds no more terms among the first 10^7 primes. Primes p that divide A024451(A000720(p)-1). - Antti Karttunen, Feb 08 2024 LINKS Table of n, a(n) for n=1..7. FORMULA a(n) = A000040(1+A369972(n)). - Antti Karttunen, Feb 08 2024 EXAMPLE Since 1/2 + 1/3 + 1/5 + 1/7 + 1/11 + 1/13 + 1/17 = 716167/510510 and 19 divides 716167, 19 is in the sequence. Since there are no primes less than 2, the sum of their reciprocals is 0/1, and as 2 divides 0, it is therefore included as the first term of this sequence. - Antti Karttunen, Feb 08 2024 PROG (PARI) lista(nn) = my(s = 0); forprime(p=2, nn, if (!(numerator(s) % p), print1(p, ", ")); s += 1/p; ); \\ Michel Marcus, Oct 09 2017, edited for the new, more inclusive definition by Antti Karttunen, Feb 08 2024 CROSSREFS Cf. A000040, A000720, A024451, A120289, A369972, A369973. Sequence in context: A140761 A077323 A215274 * A304782 A184435 A112266 Adjacent sequences: A293454 A293455 A293456 * A293458 A293459 A293460 KEYWORD more,nonn AUTHOR Logan J. Kleinwaks, Oct 09 2017 EXTENSIONS Relaxed the definition to include 2 as the first term - Antti Karttunen, Feb 08 2024 STATUS approved

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

Last modified April 22 09:25 EDT 2024. Contains 371894 sequences. (Running on oeis4.)