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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A090340 Difference between the sums of the prime factors, including multiplicity, of n and those of n + 1. 3
 -2, -1, -1, -1, 0, -2, 1, 0, -1, -4, 4, -6, 4, 1, 0, -9, 9, -11, 10, -1, -3, -10, 14, -1, -5, 6, -2, -18, 19, -21, 21, -4, -5, 7, 2, -27, 16, 5, 5, -30, 29, -31, 28, 4, -14, -22, 36, -3, 2, -8, 3, -36, 42, -5, 3, -9, -9, -28, 47, -49, 28, 20, 1, -6, 2, -51, 46, -5, 12, -57, 59, -61, 34, 26, -10, 5, 0, -61, 66, 1, -31, -40, 69, -8, -23, 13 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS If a(n) = 0 then n is a Ruth-Aaron number. - Andrew Slattery, Apr 15 2020 LINKS Table of n, a(n) for n=1..86. FORMULA a(n) = sopfr(n) - sopfr(n+1), where sopfr = A001414. - Wesley Ivan Hurt, Aug 10 2016 EXAMPLE a(24)=-1 because 24=2*2*2*3, 25=5*5 and (2+2+2+3)-(5+5)=-1. CROSSREFS Cf. A001414 (sopfr), A090341, A090342, A090343. Ruth-Aaron numbers: A039752. Sequence in context: A135997 A026609 A286935 * A287364 A340676 A117162 Adjacent sequences: A090337 A090338 A090339 * A090341 A090342 A090343 KEYWORD sign AUTHOR Charles K. Layman (cklayman(AT)juno.com), Nov 25 2003 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 May 28 04:05 EDT 2023. Contains 362992 sequences. (Running on oeis4.)