A347260 Lexicographically earliest sequence S of distinct nonnegative terms such that the digits of (a(n) + a(n+1)) are the first n digits of S.

1, 0, 10, 91, 919, 9190, 91901, 919018, 9190173, 91901746, 919017453, 9190174538, 91901745381, 919017453809, 9190174538100, 91901745380991, 919017453809928, 9190174538099262, 91901745380992639, 919017453809926380, 9190174538099263811, 91901745380992638108, 919017453809926381082, 9190174538099263810819, 91901745380992638108199, 919017453809926381081990

Offset: 1

Author

Eric Angelini and Carole Dubois, Sep 30 2021

Keywords

• base
• nonn

Comments

A self-describing sequence.

Examples

			a(1) + a(2) = 1 + 0 = 1 and this 1 is the first digit of S;
a(2) + a(3) = 0 + 10 = 10 and 1, 0 are the first 2 digits of S;
a(3) + a(4) = 10 + 91 = 101 and 1, 0, 1 are the first 3 digits of S;
a(4) + a(5) = 91 + 919 = 1010 and 1, 0, 1, 0 are the first 4 digits of S;
a(5) + a(6) = 919 + 9190 = 10109 and 1, 0, 1, 0, 9 are the first 5 digits of S;
etc.
		

Links

• Dominic McCarty, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A300000.

Programs

Python

a=[1]
while len(a)<20:a.append(int("".join(map(str,a))[:len(a)])-a[-1])
print(a) # Dominic McCarty, Mar 21 2025