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A144777
Integers having decimal digital mean equal to zero.
9
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
OFFSET
1,1
COMMENTS
Define the digital mean of n in base b, dm(b, n), to be (Sum_{i=1..d} 2*d_i - (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 dm(10, n) = 0; that is, two times the sum of the digits is equal to nine times the number of digits.
MATHEMATICA
Select[Range[200]*9, 2*DigitSum[#] == 9*IntegerLength[#] &] (* Paolo Xausa, May 17 2024 *)
CROSSREFS
Sequence in context: A090064 A082804 A262277 * A296130 A284811 A257001
KEYWORD
base,easy,nonn
AUTHOR
Reikku Kulon, Sep 21 2008
STATUS
approved