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

Author

Ali Sada, Aug 23 2025

Keywords

• nonn
• base
• new

Examples

			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.
		

Crossrefs

Cf. A334676.

Programs

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