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A262229 Numbers m such that A000217(m) > A062918(m). 1
10, 11, 87, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 895, 896, 897, 898, 899, 900, 901, 902, 903, 904, 905, 906, 907, 908, 909, 910, 911, 912, 913, 914, 915, 916, 917, 918, 919, 920, 921, 922, 923, 924, 925, 926, 927, 928, 929, 930, 931 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The sum of the digit reversals of first n natural numbers (A062918) is equal to the sum of the first n natural numbers (A000217) for n=1 to 9. Then 10 is the first time that A000217(m) > A062918(m).

LINKS

Michel Marcus, Table of n, a(n) for n = 1..1274

Didier Müller, Somme des premiers entiers inversés, Défi Turing (in French).

EXAMPLE

For m=10, 1+2+3+4+5+6+7+8+9+10 is > 1+2+3+4+5+6+7+8+9+01, so 10 is a term.

MATHEMATICA

lim = 931; t = Rest@ Accumulate[Range[0, lim]]; s = Accumulate[Table[FromDigits[Reverse[IntegerDigits@ n]], {n, 1, lim + 1}]]; Select[Range@ lim, t[[#]] > s[[#]] &] (* Michael De Vlieger, Sep 15 2015, after Harvey P. Dale at A000217 and Enrique Pérez Herrero at A062918 *)

PROG

(PARI) isok(n) = n*(n+1)/2 - sum(k=1, n, eval(concat(Vecrev(Str(k))))) > 0;

(MAGMA) [m: m in [0..10^3] | m*(m+1)/2 gt &+[Seqint(Reverse(Intseq(i))): i in [0..m]]]; // Bruno Berselli, Sep 16 2015

CROSSREFS

Cf. A000217, A062918.

Sequence in context: A037958 A041214 A228381 * A086457 A046851 A045953

Adjacent sequences:  A262226 A262227 A262228 * A262230 A262231 A262232

KEYWORD

nonn,base

AUTHOR

Michel Marcus, Sep 15 2015

STATUS

approved

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Last modified December 11 05:41 EST 2017. Contains 295868 sequences.