A025556 a(n) = sum of the exponents in the prime factorization of LCM{1,3,6,...,C(n+1,2)}.

0, 1, 2, 3, 3, 4, 5, 6, 6, 7, 7, 8, 8, 8, 9, 10, 10, 11, 11, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 17, 17, 17, 17, 17, 18, 18, 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 24, 24, 25, 25, 25, 26, 26, 26, 27, 27, 27, 27, 28, 28, 29, 29, 29, 29, 29, 29, 30

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Links

• Index entries for sequences related to lcm's

Crossrefs

Cf. A001222, A025528, A025555.

Programs

PARI

a025555(n) = my(s=1); for(k=1, n, s=lcm(s, k*(k+1)/2)); s \\ after Edward Jiang in A025555
a(n) = bigomega(a025555(n)) \\ Felix Fröhlich, Sep 06 2019

Formula

a(n) = A001222(A025555(n)). - Sean A. Irvine, Sep 06 2019

a(n) = A025528(n+1)-1. - Pontus von Brömssen, Sep 28 2024

Extensions

More terms from Sean A. Irvine, Sep 06 2019