A063072 Sum of divisors of Ramanujan's highly composite numbers, or sigma(A002182(n)).

1, 3, 7, 12, 28, 60, 91, 124, 168, 360, 546, 744, 1170, 2418, 2880, 4368, 5952, 9360, 19344, 28800, 39312, 59520, 79248, 99944, 112320, 180048, 203112, 232128, 345600, 471744, 714240, 950976, 1199328, 1451520, 2160576, 2437344, 2926080

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..50 from Harry J. Smith)

Formula

a(n) = A000203(A002182(n)). - Michel Marcus, Jun 28 2018

Mathematica

s={}; dm=0; Do[d = DivisorSigma[0, n]; If[d > dm, dm=d; AppendTo[s, DivisorSigma[1, n]]], {n, 1, 10^5}]; s (* Amiram Eldar, Jun 28 2019 *)

Prog

(PARI) a=0; j=[]; for(n=1, 200000, b=numdiv(n); if(b>a, a=b; j=concat(j, sigma(n)))); j
(PARI) { n=a=0; for (m=1, 10^9, b=numdiv(m); if(b>a, a=b; write("b063072.txt", n++, " ", sigma(m)); if (n==50, break)) ) } \\ Harry J. Smith, Aug 16 2009

Crossrefs

Cf. A000005, A004394, A002182, A002183, A002473, A000203.

Sequence in context: A196917 A256259 A182941 * A007626 A193297 A377572

Adjacent sequences: A063069 A063070 A063071 * A063073 A063074 A063075

Keyword

easy,nonn

Author

Jason Earls, Aug 02 2001

Extensions

More terms from Reiner Martin, Dec 22 2001

Status

approved