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

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1020, 11, 1023, 31, 1024, 51, 1063, 71, 1028, 91, 20, 21012, 12, 220035, 24, 20025, 26, 20074, 28, 220095, 230, 13, 300025, 33, 10413, 53, 300026, 73, 300085, 93, 40, 1041, 42, 3000461, 14, 5041, 46, 700451, 48, 9041, 520, 15

Offset: 0

Author

Sebastian Karlsson, Nov 17 2021

Keywords

• base
• sign

Examples

			a(10) = 1020, because 1020 is the first number k such that A348179(k) = 10.
a(1111111110) = -1 (found by _Kevin Ryde_).
		

Links

• David A. Corneth, Table of n, a(n) for n = 0..10000 (first 453 terms from Sebastian Karlsson)

Crossrefs

Cf. A336668, A348179, A349422.

Programs

Python

def A348179(n):
    s, l = str(n), len(str(n))
    return int("".join(s[(i + int(s[i])) % l] for i in range(l)))
terms = {}
for n in range(0, 3000462): # 3000462 to get all terms of the data-section without -1s.
    if (k := A348179(n)) not in terms: terms[k] = n
for n in range(0, 52):
    try: print(terms[n], end=", ")
    except: print(-1, end=", ") # These -1s are conjectured.