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A109061 To compute a(n) we first write down 9^n 1's in a row. Each row takes the rightmost 9th 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 9th part. The single element in the last row is a(n). 6
1, 1, 9, 693, 476121, 2940705927, 163444130390781 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..6.

EXAMPLE

For example, for n=3 the array, from 2nd row, follows:

1..2..3.....70..71..72..73..74..75..76..77..78..79..80..81

........................73.147.222.298.375.453.532.612.693

.......................................................693

Therefore a(3)=693.

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=8*nops(L)/9+1..j), j=8*nops(L)/9+1..nops(L))]; a:=f([seq(1, j=1..9^n)]); while nops(a)>9 do a:=f(a) end do; a[9]; end proc;

CROSSREFS

Cf. A107354, A109055, A109056, A109057, A109058, A109059, A109060, A109062.

Sequence in context: A053973 A059492 A322488 * A282181 A053515 A120816

Adjacent sequences:  A109058 A109059 A109060 * A109062 A109063 A109064

KEYWORD

nonn

AUTHOR

Augustine O. Munagi, Jun 17 2005

STATUS

approved

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Last modified October 18 23:39 EDT 2019. Contains 328211 sequences. (Running on oeis4.)