OFFSET
1,1
LINKS
Giorgos Kalogeropoulos, Table of n, a(n) for n = 1..5000
Eric Angelini, Cumulative Sums, personal blog.
EXAMPLE
a(1) = 91
a(1) + a(2) = 101
a(1) + a(2) + a(3) = 102
a(1) + a(2) + a(3) + a(4) = 204
a(1) + a(2) + a(3) + a(4) + a(5) = 224
a(1) + a(2) + a(3) + a(4) + a(5) + a(6) = 228; etc.
The succession of the above results is:
91, 101, 102, 204, 224, 228, ...
The first terms of the sequence are:
91, 10, 1, 102, 20, 4, 2, 24, 22, 8, ...
We see that the successive digits are the same in the two sequences.
MATHEMATICA
Nest[(a=#; AppendTo[a, (new=Flatten[IntegerDigits/@Accumulate@#][[Length@Flatten[IntegerDigits/@a]+1;; ]];
k=1; While[MemberQ[a, FromDigits@new[[;; k]]]||new[[k+1]]==0, k++]; FromDigits@new[[;; k]])])&, {91, 10}, 77] (* Giorgos Kalogeropoulos, Aug 05 2023 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Eric Angelini, Aug 01 2023
EXTENSIONS
More terms from Giorgos Kalogeropoulos, Aug 05 2023
a(28) on corrected by Giorgos Kalogeropoulos, Aug 05 2023
STATUS
approved