A327264 Numbers k with digit_sum(2*k) = digit_sum(2+k).

2, 11, 20, 47, 74, 83, 92, 101, 110, 137, 146, 164, 173, 182, 191, 200, 227, 236, 245, 254, 263, 272, 281, 290, 317, 326, 335, 353, 362, 371, 380, 407, 416, 425, 452, 461, 470, 497, 524, 533, 542, 569, 578, 614, 623, 632, 641, 659, 668

Offset

1,1

Comments

The graph is fairly interesting, as the terms are clustered together linearly in different sections.

The sequence is infinite since it contains all the terms 2*10^k, for k >= 0. - Metin Sariyar, Sep 16 2019

Links

Max Lacoma, Table of n, a(n) for n = 1..10000

Mathematica

Select[Range@700, Equal @@ Plus @@@ IntegerDigits[{2 #, 2 + #}] &] (* Giovanni Resta, Sep 16 2019 *)

Prog

(MATLAB - Checks up to n=10000)
n = 0;
x = [];
while n < 10000
    two_n = sum(str2num(num2str(2*n)'));
    two_plus_n = sum(str2num(num2str(2+n)'));
    if two_n == two_plus_n
        x(numel(x)+1) = n;
    end
    n = n+1;
end
x
(PARI) isok(k) = sumdigits(2*k) == sumdigits(k+2); \\ Michel Marcus, Sep 16 2019

Crossrefs

Cf. A007953.

Sequence in context: A092595 A175927 A116990 * A279772 A226416 A146087

Adjacent sequences: A327261 A327262 A327263 * A327265 A327266 A327267

Keyword

nonn,look,base

Author

Max Lacoma, Sep 14 2019

Status

approved