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A110394
a(1) = 1; a(n) = n times (9's complement of a(n-1)).
3
1, 16, 249, 3000, 34995, 390024, 4269825, 45841392, 487427463, 5125725360, 53617021029, 556595747640, 5764255280667, 59300426070648, 610493608940265, 6232102256955744, 64054261631752335, 647023290628457952
OFFSET
1,2
COMMENTS
a(1)=1; a(n)=n*[99...9 - a(n-1)] for n>1 (99...9 and a[n-1] have the same number of digits). - Emeric Deutsch, Jul 31 2005
LINKS
EXAMPLE
a(4) = 4 times 9's complement of a(3) = 4*(999-249) = 3000.
MAPLE
s:=proc(m) nops(convert(m, base, 10)) end: a[1]:=1: for n from 2 to 21 do a[n]:=n*(10^s(a[n-1])-1-a[n-1]) od: seq(a[n], n=1..21); # Emeric Deutsch, Jul 31 2005
# second Maple program:
a:= proc(n) option remember; `if`(n=1, 1,
n*(p-> 10^length(p)-1-p)(a(n-1)))
end:
seq(a(n), n=1..30); # Alois P. Heinz, Sep 22 2015
MATHEMATICA
nxt[{n_, a_}]:={n+1, (n+1)(FromDigits[PadRight[{}, IntegerLength[a], 9]]-a)}; NestList[nxt, {1, 1}, 20][[;; , 2]] (* Harvey P. Dale, Mar 13 2024 *)
CROSSREFS
Sequence in context: A183431 A222383 A282312 * A220459 A160446 A317894
KEYWORD
base,easy,nonn
AUTHOR
Amarnath Murthy, Jul 29 2005
EXTENSIONS
More terms from Emeric Deutsch, Jul 31 2005
STATUS
approved