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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A275722 Numbers n for which A003961(n+1) < A003961(n). 5

%I

%S 4,6,8,9,10,12,16,18,20,21,22,24,27,28,30,32,33,36,40,42,45,46,48,50,

%T 52,54,56,57,58,60,64,66,68,70,72,75,76,78,81,82,84,88,90,92,93,96,98,

%U 100,102,104,105,106,108,110,112,114,117,120,126,128,130,132,133,135,136,138,140,141,144,147,148,150,152,153,154

%N Numbers n for which A003961(n+1) < A003961(n).

%C Positions of the descents in permutation A048673.

%H Antti Karttunen, <a href="/A275722/b275722.txt">Table of n, a(n) for n = 1..16384</a>

%t f[n_] := Times @@ Map[Prime[PrimePi@ First[#] + 1]^Last[#] &, FactorInteger@ n]; Select[Range@ 154, f@ # > f[# + 1] &] (* _Michael De Vlieger_, Aug 07 2016 *)

%o (Scheme, with _Antti Karttunen_'s IntSeq-library)

%o (define A275722 (MATCHING-POS 1 1 (lambda (n) (< (A003961 (+ 1 n)) (A003961 n)))))

%Y One less than A275718.

%Y Complement: A275721.

%Y Cf. A003961, A048673, A275719.

%K nonn

%O 1,1

%A _Antti Karttunen_, Aug 07 2016

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 12 13:04 EDT 2020. Contains 335661 sequences. (Running on oeis4.)