A388266 Primitive terms of A388265.

6, 20, 28, 104, 272, 304, 368, 464, 496, 572, 650, 945, 1190, 1575, 1952, 2024, 2205, 2368, 2552, 2990, 3008, 3128, 3392, 3410, 3608, 3944, 4070, 4288, 4970, 5312, 5355, 5390, 5504, 5985, 6208, 6248, 6848, 7232, 7245, 7425, 7568, 7832, 8024, 8085, 8128, 8228, 8925, 9272, 9555, 9590, 9944, 10112, 10184, 11132, 11792

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for sequences related to primorial base.

Index entries for sequences related to sigma(n).

Index entries for sequences where odd perfect numbers must occur, if they exist at all.

Prog

(PARI)
is_A388265(n) = { my(s=sigma(n), p=2); s -= n; while(n, if(min(n%p, s%p) != (n%p), return(0)); n = n\p; s = s\p; p = nextprime(1+p)); (1); };
is_A388266(n) = if(!is_A388265(n), 0, fordiv(n, d, if(d<n && is_A388265(d), return(0))); (1));

Crossrefs

Subsequence of A388265.

Cf. also A388035, A388037, A388272.

Sequence in context: A376874 A388030 A389712 * A388272 A242341 A140738

Adjacent sequences: A388263 A388264 A388265 * A388267 A388268 A388269

Keyword

nonn,base

Author

Antti Karttunen, Sep 16 2025

Status

approved