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A089905 Sum of digits of numbers between 0 and (3/9)*(10^n-1). 6
0, 6, 183, 3285, 47787, 627789, 7777791, 92777793, 1077777795, 12277777797, 137777777799, 1527777777801, 16777777777803, 182777777777805, 1977777777777807, 21277777777777809, 227777777777777811 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

From a suggestion of Yalcin Aktar

LINKS

Table of n, a(n) for n=0..16.

Index entries for linear recurrences with constant coefficients, signature (22,-141,220,-100).

FORMULA

a(n) = s(3, n-1) where s(a, k)=a*(k+1)+a^2*sum(i=0, k, i*10^(k-i))+sum(i=0, k, 5*a*(9*(k-i)+a- 1)*10^(k-i-1))

Terms satisfy a(n) = 22a(n-1)-141a(n-2)+220a(n-3)-100a(n-4) - T. D. Noe, Nov 08 2006

a(n) = (-11/9*(-1+10^n)+1/2*(4+3*10^n)*n). G.f.: 3*x*(5*x+1)*(7*x+2) / ((x-1)^2*(10*x-1)^2). - Colin Barker, Jun 14 2013

MATHEMATICA

LinearRecurrence[{22, -141, 220, -100}, {0, 6, 183, 3285}, 20] (* Harvey P. Dale, Apr 19 2013 *)

CROSSREFS

Cf. A089903, A089904, A089906, A087330, A089906, A089907, A089908, A034967.

Sequence in context: A251671 A064120 A041429 * A222887 A012208 A012181

Adjacent sequences:  A089902 A089903 A089904 * A089906 A089907 A089908

KEYWORD

nonn,base,easy

AUTHOR

Benoit Cloitre, Nov 14 2003

EXTENSIONS

Corrected by T. D. Noe, Nov 08 2006

STATUS

approved

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Last modified December 1 16:44 EST 2021. Contains 349430 sequences. (Running on oeis4.)