A074303 Sum of squares of digits of n is equal to the largest prime factor of n reversed, where the largest prime factor is not a palindrome.

123, 705, 931, 1230, 1239, 1521, 2528, 2812, 4233, 4665, 6264, 7050, 7157, 7316, 8151, 9310, 11315, 11745, 12300, 12390, 13056, 14104, 14418, 15192, 15210, 15281, 16643, 17444, 17478, 18827, 20128, 20953, 21414, 21437, 23001, 23275, 24123

Offset

0,1

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Example

1239 = 3.7.'59' and 1^2 + 2^2 + 3^2 + 9^2 = 95.

Mathematica

ssdQ[n_]:=Module[{lpf=FactorInteger[n][[-1, 1]]}, lpf!=IntegerReverse[lpf] && IntegerReverse[lpf]==Total[IntegerDigits[n]^2]]; Select[Range[ 25000], ssdQ] (* The program uses the IntegerReverse function from Mathematica version 10 *) (* Harvey P. Dale, Apr 11 2016 *)

Crossrefs

Sequence in context: A031689 A181679 A193251 * A077379 A135475 A233119

Adjacent sequences: A074300 A074301 A074302 * A074304 A074305 A074306

Keyword

base,nonn

Author

Jason Earls, Sep 21 2002

Status

approved