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A109056 To compute a(n) we first write down 4^n 1's in a row. Each row takes the rightmost 4th part of the previous row and each element in it equals sum of the elements of the previous row starting with the first of the rightmost 4th part. The single element in the last row is a(n). 7
1, 1, 4, 58, 3236, 713727, 627642640, 2205897096672, 31004442653082720, 1743005531132374350208 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..9.

EXAMPLE

For example, for n=3 the array looks like this:

1..1.....1..1..1..1..1..1..1..1..1..1..1..1..1..1..1..1..1

............1..2..3..4..5..6..7..8..9.10.11.12.13.14.15.16

...............................................13.27.42.58

........................................................58

Therefore a(4)=58.

MAPLE

proc(n::nonnegint) local f, a; if n=0 or n=1 then return 1; end if; f:=L->[seq(add(L[i], i=3*nops(L)/4+1..j), j=3*nops(L)/4+1..nops(L))]; a:=f([seq(1, j=1..4^n)]); while nops(a)>4 do a:=f(a) end do; a[4]; end proc;

CROSSREFS

Sequence in context: A216352 A295406 A229528 * A326944 A155204 A290765

Adjacent sequences:  A109053 A109054 A109055 * A109057 A109058 A109059

KEYWORD

nonn

AUTHOR

Augustine O. Munagi, Jun 17 2005

STATUS

approved

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Last modified April 7 11:37 EDT 2020. Contains 333304 sequences. (Running on oeis4.)