A376904 Inverse permutation to A376903.

1, 2, 4, 3, 11, 5, 26, 8, 6, 12, 82, 7, 97, 27, 13, 9, 202, 17, 244, 10, 28, 83, 424, 18, 14, 98, 46, 29, 664, 15, 741, 38, 84, 203, 16, 19, 1182, 245, 99, 39, 1416, 20, 1584, 85, 47, 425, 1923, 21, 30, 62, 204, 100, 2463, 22, 86, 31, 246, 665, 3354, 23, 3723

Offset: 1

Author

Rémy Sigrist, Oct 09 2024

Keywords

• nonn

Examples

			A376903(42) = 88, so a(88) = 42.
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10000
• Rémy Sigrist, C++ program
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A376903.

Programs

Python

from itertools import count, islice
def agen(): # generator of terms; uses A376903gen() in A376903
    adict, n = dict(), 1
    for k, v in enumerate(A376903gen(), 1):
        if v not in adict:
            adict[v] = k
            while n in adict: yield adict[n]; n += 1
print(list(islice(agen(), 61))) # Michael S. Branicky, Oct 16 2024