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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A034174 a(n) is minimal such that prime factorizations of a(n)-n+1, ..., a(n) have same exponents. 7

%I #29 Jan 02 2023 12:30:46

%S 1,3,35,19943,204327,380480350,440738966079

%N a(n) is minimal such that prime factorizations of a(n)-n+1, ..., a(n) have same exponents.

%C The final terms of the arithmetic progressions defined in A083785. - _N. J. A. Sloane_, Oct 18 2007

%C a(8) > 10^13. - _Donovan Johnson_, Oct 20 2009. [See Reble link for an upper limit.]

%C The main entry is A034173, which should be updated whenever something relevant is added here. - _M. F. Hasler_, Oct 28 2012

%H Don Reble, <a href="http://list.seqfan.eu/oldermail/seqfan/2012-October/010353.html">a(8) < 1.9*10^42</a>, SeqFan list, Oct 23 2012

%H <a href="/index/Pri#primes_AP">Index entries for sequences related to primes in arithmetic progressions</a>

%F a(n) = A034173(n) + n - 1. - _Max Alekseyev_, Nov 10 2009

%e a(4)=19943 because 19940, ..., 19943 all have the form p^2 q r.

%o (PARI) A034174(n)={my(f); for(k=n, 9e9, f=0; for(i=0, n-1, f==(f=vecsort(factor(k-i)[, 2])) || !i || [k+=n-i-1; next(2)]); return(k))} \\ For illustrative purpose; not useful for n>=6. - _M. F. Hasler_, Oct 28 2012

%Y Diagonal of A083785. Cf. A034173, A083785, A083787. See A034173 for more.

%K hard,nonn,more

%O 1,2

%A _Dean Hickerson_, Oct 01 1998

%E a(7) from _Donovan Johnson_, Oct 20 2009

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 19 04:35 EDT 2024. Contains 371782 sequences. (Running on oeis4.)