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A144777 Integers having decimal digital mean equal to zero. 8
18, 27, 36, 45, 54, 63, 72, 81, 90, 1089, 1098, 1179, 1188, 1197, 1269, 1278, 1287, 1296, 1359, 1368, 1377, 1386, 1395, 1449, 1458, 1467, 1476, 1485, 1494, 1539, 1548, 1557, 1566, 1575, 1584, 1593, 1629, 1638, 1647, 1656, 1665, 1674, 1683, 1692, 1719 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Define the digital mean of n in base b, dm(b, n), to be sigma(i in [1, d]: d_i * 2 - (b - 1)) / (2 * d), where d is the number of digits in the base b representation of n and d_i the individual digits.

a(n) is the subset of multiples of nine for which sigma(i in [1, d]: d_i * 2 - 9) = 0; that is, two times the sum of the digits is equal to nine times the number of digits.

LINKS

Table of n, a(n) for n=1..45.

CROSSREFS

Cf. A007953, A008591

Sequence in context: A090064 A082804 A262277 * A296130 A284811 A257001

Adjacent sequences:  A144774 A144775 A144776 * A144778 A144779 A144780

KEYWORD

base,easy,nonn

AUTHOR

Reikku Kulon, Sep 21 2008

STATUS

approved

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Last modified April 14 01:17 EDT 2021. Contains 342941 sequences. (Running on oeis4.)