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!)
A181485 Indices of records in A171919 = number of solutions to n=x*y*z, x+y=z+1. 2
1, 4, 112, 144, 23400, 28224, 247104, 604800, 26812800, 2677752000, 6805814400, 165145780800, 1248124550400, 17996854730400, 388778796252000 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
The sequence lists all n such that A171919(n) > A171919(k) for all k < n.
Also the subsequence of terms of A171920 for which A171919 is larger than for all preceding values.
The actual record values are given in A181486.
a(10) > 5*10^7.
It seems highly probable that all terms of this sequence, except for a(1) = 1, are multiples of 4.
a(14) > 4*10^12. - Donovan Johnson, Jun 14 2011
a(16) > 2*10^17. - Robert Gerbicz, Apr 10 2012
LINKS
EXAMPLE
a(1) = 1 since there is no smaller value possible.
a(2) = 4 is the smallest number for which there are more than 1 = A171919(1) solutions to n = x*y*z, x + y = z + 1.
a(3) = 112 is the smallest number for which there are more than 2 = A171919(4) solutions to n = x*y*z, x + y = z + 1.
PROG
(PARI) m=0; for(n=1, 1e9, A171919(n)>m | next; m=A171919(n); print1(n", "))
CROSSREFS
Sequence in context: A214107 A202518 A212655 * A135917 A241798 A158450
KEYWORD
hard,more,nonn
AUTHOR
R. J. Mathar and M. F. Hasler, Oct 23 2010
EXTENSIONS
a(10)-a(13) from Donovan Johnson, Jun 14 2011
a(14)-a(15) from Robert Gerbicz, Apr 10 2012
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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)