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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A121413 Column 1 of triangle A121412, in which row n of T equals row (n-1) of T^(n+1) with an appended '1'. 10

%I #3 Mar 30 2012 18:36:58

%S 1,1,4,30,335,4984,92652,2065146,53636520,1589752230,52926799310,

%T 1954793723688,79297921097850,3504206787532290,167533486104374420,

%U 8615231103973721610,474145710046504872894,27806642356199323970739

%N Column 1 of triangle A121412, in which row n of T equals row (n-1) of T^(n+1) with an appended '1'.

%C Also equals column 3 of triangle A101479.

%o (PARI) {a(n)=local(A=Mat(1), B); for(m=1, n+2, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=1, B[i, j]=(A^i)[i-1, j]); )); A=B); return((A^1)[n+2, 2])}

%Y Cf. A121412 (triangle); other columns: A101483, A121414, A121415; A101479 (triangle).

%K nonn

%O 0,3

%A _Paul D. Hanna_, Aug 22 2006

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 June 8 10:34 EDT 2023. Contains 363163 sequences. (Running on oeis4.)