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URL: https://oeis.org/A060781

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A060781
a(n) = lcm(sigma(n+1), sigma(n)), where sigma = A000203.
5
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
FORMULA
a(n) = lcm(A000203(n+1), A000203(n)).
MATHEMATICA
LCM @@@ Partition[DivisorSigma[1, Range[50]], 2, 1] (* Amiram Eldar, Mar 25 2024 *)
PROG
(PARI) a(n) = { lcm(sigma(n), sigma(n+1)) } \\ Harry J. Smith, Jul 11 2009
CROSSREFS
Cf. A000203.
Sequence in context: A260815 A083543 A083538 * A083539 A237426 A066643
KEYWORD
nonn
AUTHOR
Labos Elemer, Apr 26 2001
EXTENSIONS
Name corrected by Amiram Eldar, Mar 25 2024
STATUS
approved