A387956 Composite non-semiprime solutions m to m'' = m'-1, where m' and m'' are the first and the second arithmetic derivatives of m.

10392284335, 11971434307, 39817292107, 64231546567, 72396994231

Offset

1,1

Comments

Equivalently, non-semiprime solutions for m' = q, where q is a primary pseudoperfect number (A054377). Terms a(1)-a(5) correspond to A054377(6). Term a(6) would be a solution to m' = A054377(k) with k >= 8.

All composite solutions are listed in A189803, unrestricted solutions are listed in A189710.

Links

Table of n, a(n) for n=1..5.

Example

a(1) = 10392284335 = 5 * 83 * 997 * 25117 is a solution to m' = A054377(6) = 2214502422.

Crossrefs

Subsequence of A189710 and A189803.

Cf. A003415, A054377, A390533.

Sequence in context: A259152 A371361 A135047 * A017541 A357609 A112453

Adjacent sequences: A387953 A387954 A387955 * A387957 A387958 A387959

Keyword

nonn,more,hard

Author

Max Alekseyev, Nov 09 2025

Status

approved