login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

a(1) = 1; for n > 1, a(n) is the smallest positive integer that has not yet appeared which contains all the distinct digits of the sum of all previous terms a(1)..a(n-1).
1

%I #10 Dec 22 2023 10:36:47

%S 1,10,11,2,24,48,69,156,123,4,84,235,67,348,128,103,134,1457,304,308,

%T 136,2357,1069,178,3567,10239,126,182,10247,137,13458,12345,567,2458,

%U 2068,20567,1378,45689,10348,102347,203479,4568,12456,234568,105689,3089,20689,12678,204589,1048,1023459

%N a(1) = 1; for n > 1, a(n) is the smallest positive integer that has not yet appeared which contains all the distinct digits of the sum of all previous terms a(1)..a(n-1).

%C The sequence is infinite, although it is unknown if all positive numbers eventually appear. In the first 50000 terms the smallest number not to have appeared is 3. In the same range the largest value is a(49134) = 1023548967, with the sum of all previous terms at that point being 553402987165.

%H Scott R. Shannon, <a href="/A368347/b368347.txt">Table of n, a(n) for n = 1..10000</a>

%e a(3) = 11 as the sum of the first two terms is 1 + 10 = 11, which contains the distinct digit 1, and 11 is the smallest unused number to contain 1.

%e a(4) = 2 as the sum of the first three terms is 1 + 10 + 11 = 22, which contains the distinct digit 2, and 2 is the smallest unused number to contain 2.

%e a(5) = 24 as the sum of the first four terms is 1 + 10 + 11 + 2 = 24, which contains the distinct digits 2 and 4, and 24 is the smallest unused number to contain 2 and 4.

%Y Cf. A368181, A362093, A362075, A342383, A342382.

%K nonn,base

%O 1,2

%A _Scott R. Shannon_, Dec 22 2023