cp's OEIS Frontend

A337843 a(n) is n + the number of digits in the decimal expansion of n.

%I A337843 #18 Jun 25 2025 14:50:24
%S A337843 1,2,3,4,5,6,7,8,9,10,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,
%T A337843 28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,
%U A337843 51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69
%N A337843 a(n) is n + the number of digits in the decimal expansion of n.
%C A337843 a(n) is an increasing injective sequence that is not surjective.
%C A337843 a(n) is also the sequence of numbers m that can be written as (m + number of digits of m) for some m >= 0, complement of numbers from A081552(n) for n > 1.
%C A337843 Sequence is not the same as A101947, first different term is a(77) = 79.
%F A337843 a(n) = n + A055642(n).
%e A337843 a(10) = 10 + 2 = 12.
%t A337843 a[0] = 1; a[n_] := n + IntegerLength[n]; Array[a, 100, 0] (* _Amiram Eldar_, Sep 25 2020 *)
%o A337843 (Magma) [1] cat [n + #Intseq(n): n in [1..100]];
%o A337843 (PARI) a(n) = if (n==0, 1, n + #digits(n)); \\ _Michel Marcus_, Sep 26 2020
%Y A337843 Cf. A055642, A062028, A081552, A230099.
%Y A337843 Cf. A110803 (n * the number of digits in the decimal expansion of n).
%K A337843 nonn,base
%O A337843 0,2
%A A337843 _Jaroslav Krizek_, Sep 25 2020