A353561 Prime shadows of colossally abundant numbers, A004490.

2, 4, 6, 12, 20, 30, 60, 84, 168, 336, 528, 880, 1320, 2640, 5280, 10560, 12480, 24960, 49920, 74880, 104832, 209664, 419328, 838656, 1096704, 2193408, 4386816, 8773632, 14622720, 29245440, 58490880, 116981760, 233963520, 350945280, 701890560, 784465920, 1568931840, 2465464320, 4930928640, 9861857280, 14792785920

Offset

1,1

Comments

Sequence is injective (no duplicate values occur) because A004490 is a subsequence of A025487.

Links

Amiram Eldar, Table of n, a(n) for n = 1..3367

Formula

a(n) = A181819(A004490(n)).

a(n) = A122111(A342012(n)).

Prog

(PARI)
v004490 = readvec("b004490_to.txt"); \\ Prepared from b-file of A004490 with gawk ' { print $2 } '
A004490(n) = v004490[n];
A181819(n) = factorback(apply(e->prime(e), (factor(n)[, 2])));
A353561(n) = A181819(A004490(n));

Crossrefs

Cf. A004490, A025487, A122111, A181819, A342012.

Cf. also A353562, A353568.

Sequence in context: A358100 A060798 A134320 * A329227 A294430 A294429

Adjacent sequences: A353558 A353559 A353560 * A353562 A353563 A353564

Keyword

nonn

Author

Antti Karttunen, Apr 29 2022

Status

approved