A250213 -id:A250213 - cp's OEIS frontend

A250214 Number of values of k such that prime(n) divides A241601(k).

0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 2, 1, 0, 1, 0, 0, 0, 2, 1, 0, 0, 0, 0, 1, 1, 1, 2, 0, 2, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 2, 1, 1, 2, 0, 1, 1, 0, 1, 1, 3, 3, 0, 0, 0, 0, 1, 2, 3, 1, 0, 1, 3, 0, 1, 0, 1, 1, 1, 1, 0, 2, 0, 0, 0, 0, 2, 2, 2, 0, 0, 4, 0, 0, 1, 0, 1, 2, 2, 1, 2, 0, 1, 3, 3, 1, 0, 0, 1, 1, 3, 3, 2, 0, 0, 3, 1, 1

Offset: 1

Eric Chen, Dec 26 2014

nonn

a(n) is called the weak irregular index of n-th prime, that is, the Bernoulli irregular index + Euler irregular index.
Prime(n) is a regular prime if and only if a(n) = 0.
Does every natural number appear in this sequence? For example, for the primes 491 and 1151, a(94) = a(190) = 4. (491 and 1151 are the only primes below 1800 with weak irregular index 4 or more.) However, does a(n) have a limit?

			a(8) = 1 since the 8th prime is 19, which divides A241601(11).
a(13) = 0 since the 13th prime is 41, a regular prime.
a(19) = 2 since the 19th prime is 67, which divides both A241601(27) and A241601(58).

Eric Weisstein's World of Mathematics, Irregular Pair

Cf. A091888, A091887, A250216, A000928, A120337, A128197, A250213.

cp's OEIS Frontend

A250214 Number of values of k such that prime(n) divides A241601(k).

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