A361468 a(n) = A249670(A003961(n)).

1, 12, 30, 117, 56, 40, 132, 1080, 775, 672, 182, 390, 306, 176, 1680, 9801, 380, 9300, 552, 6552, 3960, 2184, 870, 144, 2793, 408, 19500, 1716, 992, 2240, 1406, 88452, 5460, 4560, 7392, 90675, 1722, 736, 9180, 60480, 1892, 5280, 2256, 126, 43400, 1160, 2862, 32670, 16093, 3724, 456, 442, 3540, 26000

Offset

1,2

Links

Winston de Greef, Table of n, a(n) for n = 1..10000

Index entries for sequences computed from indices in prime factorization

Index entries for sequences related to sigma(n)

Formula

a(n) = A249670(A003961(n)) = A336849(n) * A341525(n).

a(n) = A361467(n) / A000290(A336850(n)).

Prog

(PARI)
A003961(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); }; \\ From A003961
A249670(n) = { my(ab = sigma(n)/n); numerator(ab)*denominator(ab); };
A361468(n) = A249670(A003961(n));

Crossrefs

Cf. A000290, A003961, A249670, A336850, A361467.

Sequence in context: A371075 A286659 A320483 * A361467 A375701 A260417

Adjacent sequences: A361465 A361466 A361467 * A361469 A361470 A361471

Keyword

nonn

Author

Antti Karttunen, Mar 20 2023

Status

approved