A147591 RootMeanSquare(digits of n) is an integer.

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 17, 22, 33, 44, 55, 66, 71, 77, 88, 99, 111, 115, 151, 157, 175, 222, 333, 444, 511, 517, 555, 571, 666, 715, 751, 777, 888, 999, 1111, 1135, 1153, 1177, 1315, 1339, 1351, 1393, 1513, 1531, 1557, 1575, 1717, 1755, 1771, 1933, 2000

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

n=1236, RMS(digits of 1351)=sqrt((1^2+3^2+5^2+1^2)/4)=sqrt(36/4)=sqrt(9)=3.

Mathematica

Select[Range[2000], IntegerQ[RootMeanSquare[IntegerDigits[#]]]&] (* Harvey P. Dale, Sep 02 2017 *)

Crossrefs

Cf. A140480

Sequence in context: A001103 A265730 A304248 * A271954 A330969 A033074

Adjacent sequences: A147588 A147589 A147590 * A147592 A147593 A147594

Keyword

base,easy,nonn

Author

Ctibor O. Zizka, Nov 08 2008

Status

approved