A358044 - OEIS

A358044

a(n) is the smallest number k such that n consecutive integers starting at k have the same number of triangular divisors (A007862).

%I #11 Jan 06 2023 10:41:37

%S 1,1,55,5402,2515069

%N a(n) is the smallest number k such that n consecutive integers starting at k have the same number of triangular divisors (A007862).

%C Any subsequent terms are > 10^10. - _Lucas A. Brown_, Jan 06 2023

%H <a href="/index/Di#divisors">Index entries for sequences related to divisors of numbers</a>

%H Lucas A. Brown, <a href="https://github.com/lucasaugustus/oeis/blob/main/A358044.py">Python program</a>.

%e 55 has 2 triangular divisors {1, 55}, 56 has 2 triangular divisors {1, 28} and 57 has 2 triangular divisors {1, 3}. These are the first 3 consecutive numbers with the same number of triangular divisors, so a(3) = 55.

%Y Cf. A000217, A006558, A007862, A045983, A045984, A324593, A324594, A338628.

%K nonn,more,hard

%O 1,3

%A _Ilya Gutkovskiy_, Oct 26 2022