A067451 Numbers such that the geometric and arithmetic mean of their decimal digits are integers.

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 19, 22, 28, 33, 44, 55, 66, 77, 82, 88, 91, 99, 111, 222, 333, 444, 555, 666, 777, 888, 999, 1111, 1128, 1182, 1199, 1218, 1281, 1339, 1393, 1812, 1821, 1919, 1933, 1991, 2118, 2181, 2222, 2288, 2811, 2828, 2882, 2899, 2989, 2998

Offset

1,2

Comments

Terms from Robert G. Wilson v.

References

Mohammad K. Azarian, An Application of the Inequality on the Means, Problem B-635, Fibonacci Quarterly, Vol. 27, No. 1, Feb. 1989, p. 87. Solution published in Vol. 28, No. 1, Feb. 1990, pp. 86-87.

Links

Table of n, a(n) for n=1..54.

Mathematica

a = {}; Do[b = Sort[IntegerDigits[n]]; c = Floor[Log[10, n]] + 1; If[b[[1]] != 0 && IntegerQ[Apply[Plus, b]/c] && IntegerQ[Apply[Times, b]^(1/c)], a = Append[a, n]], {n, 1, 10^4}]; a (* Robert G. Wilson v *)

Crossrefs

Sequence in context: A385296 A330969 A033074 * A385297 A344749 A247753

Adjacent sequences: A067448 A067449 A067450 * A067452 A067453 A067454

Keyword

base,easy,nonn

Author

Amarnath Murthy, Feb 05 2002

Status

approved