A378059 Numbers k such k | A378056(k) and (k+1) | A378056(k+1).

112375899, 871651143, 1525038515, 3524721824, 6058144224, 7616307699, 7929320399, 9778346864, 10799650575, 11536526000, 13663711775, 20596306224, 22326106256, 24442111385, 26385908912, 27394105760, 28476579725, 31552570400, 34148839725, 36045427040, 40916036304, 44037977984, 44430326199

Offset

1,1

Links

Table of n, a(n) for n=1..23.

Prog

(PARI) is1(k) = {my(d = divisors(k)); !(lcm(apply(x->x+1, d)) % k) && !(lcm(apply(x -> if(x > 1, x-1, x), d)) % k); }
lista(kmax) = {my(q1 = is1(1), q2); for(k = 2, kmax, q2 = is1(k); if(q1 && q2, print1(k-1, ", ")); q1 = q2); }

Crossrefs

Intersection of A377951 and A377953.

Subsequence of A378058.

Cf. A378055, A378056.

Sequence in context: A068538 A186552 A147581 * A281448 A171571 A208491

Adjacent sequences: A378056 A378057 A378058 * A378060 A378061 A378062

Keyword

nonn

Author

Amiram Eldar, Nov 15 2024

Status

approved