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a(n) = n + (sum of digits in base-5 representation of n).
3

%I #9 Nov 28 2020 06:22:23

%S 0,2,4,6,8,6,8,10,12,14,12,14,16,18,20,18,20,22,24,26,24,26,28,30,32,

%T 26,28,30,32,34,32,34,36,38,40,38,40,42,44,46,44,46,48,50,52,50,52,54,

%U 56,58,52,54,56,58,60,58,60,62,64,66,64,66,68,70,72,70,72,74,76,78,76,78,80,82,84,78,80,82,84,86,84

%N a(n) = n + (sum of digits in base-5 representation of n).

%C The image of this sequence is the set of nonnegative even numbers (A005843). Joshi (1973) proved that the sequence of base-q self numbers (analogous to A003052) is the sequence of odd numbers (A005408) for all odd q. - _Amiram Eldar_, Nov 28 2020

%D V. S. Joshi, Ph.D. dissertation, Gujarat Univ., Ahmedabad (India), October, 1973.

%D József Sándor and Borislav Crstici, Handbook of Number theory II, Kluwer Academic Publishers, 2004, Chapter 4, p. 384-386.

%H Donovan Johnson, <a href="/A230865/b230865.txt">Table of n, a(n) for n = 0..10000</a>

%F a(n) = n + A053824(n). - _Amiram Eldar_, Nov 28 2020

%t Table[n + Plus @@ IntegerDigits[n, 5], {n, 0, 100}] (* _Amiram Eldar_, Nov 28 2020 *)

%Y Cf. A053824, A230641.

%K nonn,base

%O 0,2

%A _N. J. A. Sloane_, Nov 05 2013