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 A064399 Numbers k whose sum of digits exceeds the sum of the digits of k^2. 5

%I

%S 39,48,49,79,149,179,249,318,348,349,389,390,399,448,449,480,489,490,

%T 498,499,548,549,579,649,679,749,789,790,795,799,849,889,895,898,899,

%U 949,1049,1096,1149,1249,1429,1488,1489,1490,1497,1498,1499,1735,1739

%N Numbers k whose sum of digits exceeds the sum of the digits of k^2.

%H Harry J. Smith, <a href="/A064399/b064399.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[ Range[ 2500 ], Apply[ Plus, IntegerDigits[ # ] ] > Apply[ Plus, IntegerDigits[ #^2 ] ] & ]

%o (PARI) SumD(x)= { local(s); s=0; while (x>9, s+=x-10*(x\10); x\=10); return(s + x) } { n=0; for (m=1, 10^9, if (SumD(m) > SumD(m^2), write("b064399.txt", n++, " ", m); if (n==1000, break)) ) } \\ _Harry J. Smith_, Sep 13 2009

%o (PARI) isok(n) = sumdigits(n) > sumdigits(n^2); \\ _Michel Marcus_, Jun 24 2018

%Y Cf. A007953, A004159.

%K base,nonn

%O 1,1

%A _Robert G. Wilson v_, Sep 28 2001

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Last modified October 23 23:51 EDT 2019. Contains 328379 sequences. (Running on oeis4.)