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

39, 48, 49, 79, 149, 179, 249, 318, 348, 349, 389, 390, 399, 448, 449, 480, 489, 490, 498, 499, 548, 549, 579, 649, 679, 749, 789, 790, 795, 799, 849, 889, 895, 898, 899, 949, 1049, 1096, 1149, 1249, 1429, 1488, 1489, 1490, 1497, 1498, 1499, 1735, 1739

Offset

1,1

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

Mathematica

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

Prog

(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
(PARI) isok(n) = sumdigits(n) > sumdigits(n^2); \\ Michel Marcus, Jun 24 2018

Crossrefs

Cf. A007953, A004159.

Sequence in context: A252711 A046512 A143746 * A235151 A050439 A199993

Adjacent sequences: A064396 A064397 A064398 * A064400 A064401 A064402

Keyword

base,nonn

Author

Robert G. Wilson v, Sep 28 2001

Status

approved