A060781 a(n) = lcm(sigma(n+1), sigma(n)) = lcm(A000203(n+1), A000203(n)).

3, 12, 28, 42, 12, 24, 120, 195, 234, 36, 84, 28, 168, 24, 744, 558, 234, 780, 420, 672, 288, 72, 120, 1860, 1302, 840, 280, 840, 360, 288, 2016, 1008, 432, 432, 4368, 3458, 1140, 840, 2520, 630, 672, 1056, 924, 1092, 936, 144, 1488, 7068, 1767, 2232, 3528

Offset

1,1

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

Index entries for sequences related to sigma(n).

Mathematica

LCM @@@ Partition[DivisorSigma[1, Range[50]], 2, 1] (* Amiram Eldar, Mar 25 2024 *)

Prog

(PARI) t=1; for (n=1, 1000, s=sigma(n+1); write("b060781.txt", n, " ", lcm(s, t)); t=s) \\ Harry J. Smith, Jul 11 2009

Crossrefs

Cf. A000203.

Sequence in context: A260815 A083543 A083538 * A083539 A237426 A066643

Adjacent sequences: A060778 A060779 A060780 * A060782 A060783 A060784

Keyword

nonn

Author

Labos Elemer, Apr 26 2001

Extensions

Name corrected by Amiram Eldar, Mar 25 2024

Status

approved