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

0,3

Links

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

Example

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

Prog

(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.

Crossrefs

Cf. A336668, A348179, A349422.

Sequence in context: A276697 A087036 A181720 * A004904 A122624 A032563

Adjacent sequences: A349420 A349421 A349422 * A349424 A349425 A349426

Keyword

base,sign

Author

Sebastian Karlsson, Nov 17 2021

Status

approved