login
This site is supported by donations to The OEIS Foundation.

 

Logo

Invitation: celebrating 50 years of OEIS, 250000 sequences, and Sloane's 75th, there will be a conference at DIMACS, Rutgers, Oct 9-10 2014.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A105071 Primes in the triangle defined by T(0,c)=1, T(1,c)=c, T(r,1)=1 and T(r,c) = T(r,c-1)+ c*(r-1)!. 0
3, 5, 11, 13, 31, 241, 337, 601, 6481, 14401, 19441, 45361, 100801, 176401, 1088641, 18144001, 32659201, 50803201, 72576001, 199584001, 958003201, 1077753601, 2155507201, 2395008001, 2594592001, 56043187201, 124540416001, 647610163201 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..27.

EXAMPLE

The host triangle T(r,c), defined recursively, starts in row r=0 with columns 1<=c<=r as:

1;

1,3;

1,5,11;

1,13,31,55;

1,49,121,217,337;

1,241,601,1081,1681,2401;'

...

The primes in the triangle enter the sequence, sorted in natural order. - R. J. Mathar, Sep 11 2011

MATHEMATICA

a[0, 0] = 1; a[1, 0] = 1; a[n_, 1] := a[n, 1] = n; a[1, m_] := a[1, m] = 1 a[n_, m_] := a[n, m] = a[n - 1, m] + (m - 1)!*n; aa = Delete[Union[Flatten[Table[Table[If[PrimeQ[a[n, m]] == True, a[n, m], 0], {n, 1, m}], {m, 0, 20}]]], 1]

CROSSREFS

Sequence in context: A237349 A095082 A216553 * A089251 A147568 A006794

Adjacent sequences:  A105068 A105069 A105070 * A105072 A105073 A105074

KEYWORD

nonn

AUTHOR

Roger L. Bagula, Apr 05 2005

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified September 18 17:06 EDT 2014. Contains 246924 sequences.