A387242 a(n) is the least k such that A334676(k) != k and the decimal string of n appears in A334676(k).

2, 42, 26, 28, 102, 32, 85, 172, 95, 20, 22, 242, 26, 28, 302, 32, 85, 236, 95, 402, 42, 442, 115, 482, 502, 522, 162, 562, 145, 260, 62, 1615, 266, 268, 712, 272, 148, 772, 278, 802, 82, 842, 215, 882, 902, 92, 235, 962, 245, 1002, 102, 1042, 265, 1078, 1102, 112, 285, 1162

Offset

1,1

Links

Table of n, a(n) for n=1..58.

Example

A334676(242) = 121, the first term whose decimal expansion contains the substring "12"; hence a(12) = 242.
A334676(21) = A334676(42) = 21 contains "2" but a(2) = 42 since the first does not satisfy A334676(k) != k.

Prog

(Python) # uses A334676() and neighs() from A334676
from itertools import count, islice
def subs(s): yield from (s[i:j] for i in range(len(s)) for j in range(i+1, len(s)+1))
def agen(): # generator of terms
    adict, n = dict(), 1
    for k in count(1):
        v = A334676(k)
        if v != k:
            for t in subs(str(v)):
                if (ti:=int(t)) not in adict:
                    adict[ti] = k
                    while n in adict:
                        yield adict[n]
                        n += 1
print(list(islice(agen(), 70))) # Michael S. Branicky, Aug 23 2025

Crossrefs

Cf. A334676.

Sequence in context: A076391 A348773 A393592 * A130201 A076392 A291173

Adjacent sequences: A387239 A387240 A387241 * A387243 A387244 A387245

Keyword

nonn,base

Author

Ali Sada, Aug 23 2025

Status

approved