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A349423 Index of first occurrence of n in A348179, or -1 if n never appears.

%I A349423 #20 Apr 18 2022 13:58:23
%S A349423 0,1,2,3,4,5,6,7,8,9,1020,11,1023,31,1024,51,1063,71,1028,91,20,21012,
%T A349423 12,220035,24,20025,26,20074,28,220095,230,13,300025,33,10413,53,
%U A349423 300026,73,300085,93,40,1041,42,3000461,14,5041,46,700451,48,9041,520,15
%N A349423 Index of first occurrence of n in A348179, or -1 if n never appears.
%H A349423 David A. Corneth, <a href="/A349423/b349423.txt">Table of n, a(n) for n = 0..10000</a> (first 453 terms from Sebastian Karlsson)
%e A349423 a(10) = 1020, because 1020 is the first number k such that A348179(k) = 10.
%e A349423 a(1111111110) = -1 (found by _Kevin Ryde_).
%o A349423 (Python)
%o A349423 def A348179(n):
%o A349423     s, l = str(n), len(str(n))
%o A349423     return int("".join(s[(i + int(s[i])) % l] for i in range(l)))
%o A349423 terms = {}
%o A349423 for n in range(0, 3000462): # 3000462 to get all terms of the data-section without -1s.
%o A349423     if (k := A348179(n)) not in terms: terms[k] = n
%o A349423 for n in range(0, 52):
%o A349423     try: print(terms[n], end=", ")
%o A349423     except: print(-1, end=", ") # These -1s are conjectured.
%Y A349423 Cf. A336668, A348179, A349422.
%K A349423 base,sign
%O A349423 0,3
%A A349423 _Sebastian Karlsson_, Nov 17 2021