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 A250216 Weak irregular primes. A prime is weak irregular iff it is a Bernoulli irregular prime or an Euler irregular prime. 5
 19, 31, 37, 43, 47, 59, 61, 67, 71, 79, 101, 103, 131, 137, 139, 149, 157, 193, 223, 233, 241, 251, 257, 263, 271, 277, 283, 293, 307, 311, 347, 349, 353, 359, 373, 379, 389, 401, 409, 419, 421, 433, 461, 463, 467, 491, 509, 523, 541, 547, 557, 563, 571, 577, 587, 593 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes p which divide A241601(k) for some k. LINKS Table of n, a(n) for n=1..56. Peter Luschny, Irregular Bernoulli and Euler Primes. The Prime Pages, Irregular Primes The Prime Pages, Euler Irregular MATHEMATICA pmax = 593; m0 = 200; dm = 100; b[n_] := Numerator[BernoulliB[2 n]/(2 n)]; c[n_] := Numerator[SeriesCoefficient[Log[Tan[x]+1/Cos[x]], {x, 0, 2n+1}]]; (* a1 = A241601 *) a1[0] = 1; a1[n_] := a1[n] = If[EvenQ[n], b[n/2] // Abs, c[(n - 1)/2]]; f[m_] := f[m] = Module[{}, aa = Table[a1[n], {n, 0, m}]; okQ[p_] := AnyTrue[aa, Divisible[#, p] &]; Reap[For[p = 2, p <= pmax, p = NextPrime[p], If[okQ[p], Sow[p]]]][[2, 1]]]; f[m = m0]; f[m = m + dm]; While[Print["m = ", m]; f[m] != f[m - dm], m = m + dm]; A250216 = f[m] (* Jean-François Alcover, Jul 23 2019 *) CROSSREFS Cf. A000928, A120337, A128197. Sequence in context: A316678 A330275 A038672 * A125148 A214798 A040066 Adjacent sequences: A250213 A250214 A250215 * A250217 A250218 A250219 KEYWORD nonn AUTHOR Eric Chen, Dec 24 2014 STATUS approved

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Last modified June 3 18:04 EDT 2023. Contains 363116 sequences. (Running on oeis4.)