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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; internal format)
OFFSET

0,3

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: A054327 A053973 A059492 * A053515 A120816 A161585

Adjacent sequences:  A109058 A109059 A109060 * A109062 A109063 A109064

KEYWORD

nonn

AUTHOR

A. O. Munagi (amunagi(AT)yahoo.com), Jun 17 2005

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Last modified February 14 13:08 EST 2012. Contains 205623 sequences.