OFFSET
1,1
COMMENTS
Terms k such that the distinct prime divisors of k*(k+1) are consecutive primes are 35, 384, 539, 4374, ... These are also terms of A141399.
LINKS
David A. Corneth, Table of n, a(n) for n = 1..741 (terms <= 10^20)
EXAMPLE
35 = 5 * 7 is a term since 5 and 7 are consecutive primes, 35 + 1 = 36 = 2^2 * 3^2 and 2 and 3 are also consecutive primes.
MATHEMATICA
q[n_] := Module[{p = FactorInteger[n][[;; , 1]], np}, np = Length[p]; np > 1 && PrimePi[p[[-1]]] - PrimePi[p[[1]]] == np - 1]; s = {}; n = 1; q1 = q[1]; Do[q2 = q[n]; If[q1 && q2, AppendTo[s, n - 1]]; q1 = q2; n++, {10^5}]; s
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Aug 06 2021
STATUS
approved