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 A227224 Numbers n such that n*(sum of digits of n) is a perfect square. 1
 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 24, 36, 48, 75, 81, 100, 121, 144, 147, 150, 169, 192, 196, 200, 225, 242, 288, 300, 320, 324, 363, 375, 400, 441, 484, 500, 507, 512, 529, 600, 640, 648, 700, 704, 735, 800, 832, 882, 900, 960, 961, 1014, 1083, 1088, 1200, 1250, 1452, 1458, 1521, 1681, 1815 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS EXAMPLE 375*(3+7+5) = 5625 = 75^2. So, 375 is a member of this sequence. MATHEMATICA Select[Range[0, 1815], IntegerQ@ Sqrt[# Plus @@ IntegerDigits@ #] &] (* Michael De Vlieger, Apr 12 2015 *) PROG (Python) def DS(n): s = 0 for i in str(n): s += int(i) return s for n in range(10**3): k = 0 while k**2 <= n*DS(n): if k**2 == n*DS(n): print(n, end=', ') break else: k += 1 # Edited by Derek Orr Apr 10 2015 (Magma) [n: n in [0..1000] | IsSquare(n*(&+Intseq(n)))]; // Vincenzo Librandi, Sep 20 2013 (PARI) for(n=0, 2000, s=sumdigits(n); if(issquare(n*s), print1(n, ", "))) \\ Derek Orr, Apr 10 2015 (Sage) [x for x in [0..2000] if is_square(x*sum(Integer(x).digits(base=10)))] # Bruno Berselli, May 25 2015 CROSSREFS Cf. A007953. Sequence in context: A138141 A228017 A346535 * A236750 A001102 A051004 Adjacent sequences: A227221 A227222 A227223 * A227225 A227226 A227227 KEYWORD nonn,base,easy AUTHOR Derek Orr, Sep 19 2013 EXTENSIONS More terms from Derek Orr, Apr 10 2015 STATUS approved

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Last modified April 1 19:13 EDT 2023. Contains 361695 sequences. (Running on oeis4.)