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

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 60th year, we have over 367,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A354928 Numbers k such that A047994(k) = A344005(k). 4
 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 16, 17, 18, 19, 22, 23, 25, 26, 27, 29, 31, 32, 34, 37, 38, 41, 43, 46, 47, 49, 50, 53, 54, 58, 59, 61, 62, 64, 67, 71, 73, 74, 79, 81, 82, 83, 86, 89, 94, 97, 98, 101, 103, 106, 107, 109, 113, 118, 121, 122, 125, 127, 128, 131, 134, 137, 139, 142, 146, 149, 151, 157, 158 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Table of n, a(n) for n=1..76. MATHEMATICA f[p_, e_] := p^e - 1; uphi[n_] := Times @@ f @@@ FactorInteger[n]; uphi[1] = 1; q[n_] := Module[{m = 1, u = uphi[n]}, While[m <= u && ! Divisible[m*(m + 1), n], m++]; m == u]; Select[Range[160], q] (* Amiram Eldar, Jun 13 2022 *) PROG (PARI) A047994(n) = { my(f=factor(n)~); prod(i=1, #f, (f[1, i]^f[2, i])-1); }; A344005(n) = for(m=1, oo, if((m*(m+1))%n==0, return(m))); \\ From A344005 A354924(n) = (A047994(n)==A344005(n)); isA354928(n) = A354924(n); CROSSREFS Cf. A346608 (complement), A354924 (characteristic function). Cf. A047994, A344005. Positions of zeros in A346607. Sequence in context: A135393 A299703 A342256 * A195044 A033112 A049813 Adjacent sequences: A354925 A354926 A354927 * A354929 A354930 A354931 KEYWORD nonn AUTHOR Antti Karttunen, Jun 13 2022 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 December 6 19:52 EST 2023. Contains 367614 sequences. (Running on oeis4.)