OFFSET
1,2
COMMENTS
Numbers k such that k and k+1 are both terms in A377950.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1000
MATHEMATICA
q[n_] := q[n] = Divisible[LCM @@ (Divisors[n] + 1), n]; Select[Range[4*10^6], q[#] && q[# + 1] &]
PROG
(PARI) is1(k) = !(lcm(apply(x->x+1, divisors(k))) % k);
lista(kmax) = {my(q1 = is1(1), q2); for(k = 2, kmax, q2 = is1(k); if(q1 && q2, print1(k-1, ", ")); q1 = q2); }
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Nov 12 2024
STATUS
approved