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 A175396 Numbers n such that the sum of the squares of its digits is a perfect square. 7
 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 34, 40, 43, 50, 60, 68, 70, 80, 86, 90, 100, 122, 148, 184, 200, 212, 221, 236, 244, 263, 269, 296, 300, 304, 326, 340, 362, 366, 400, 403, 418, 424, 430, 442, 447, 474, 481, 488, 500, 600, 608, 623, 629, 632, 636, 663 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Previous name was: Numbers n such that Sum_{i=1..r, x(i)^2} is a perfect square, where x(i) = digits of n. r=1+floor(log_10 n). LINKS Christian N. K. Anderson, Table of n, a(n) for n = 1..10000 EXAMPLE n=34, 3*3+4*4=25 is a perfect square so n=34 belongs to the sequence. n=122, 1*1+2*2+2*2=9 is a perfect square so n=122 belongs to the sequence. MATHEMATICA Select[Range[0, 666], IntegerQ[Sqrt[Plus @@ (IntegerDigits[#]^2)]] &] (* Ivan Neretin, Aug 03 2015 *) PROG (PARI) isok(n) = {digs = Vec(Str(n)); issquare(sum(i=1, #digs, eval(digs[i])^2))} \\ Michel Marcus, Jun 02 2013 CROSSREFS Cf. A084561. Sequence in context: A108652 A140665 A069024 * A107085 A212499 A244890 Adjacent sequences:  A175393 A175394 A175395 * A175397 A175398 A175399 KEYWORD base,easy,nonn AUTHOR Ctibor O. Zizka, Apr 30 2010 EXTENSIONS Corrected and extended by Neven Juric, Jul 12 2010 Simpler definition by Michel Marcus, Jun 02 2013 STATUS approved

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Last modified July 3 10:20 EDT 2020. Contains 335417 sequences. (Running on oeis4.)