A351162 a(1)=2048. For n>1, a(n) is the LCM of a(n-1) and A140635(a(n-1)).

2048, 30720, 645120, 7096320, 92252160, 1383782400, 23524300800, 446961715200, 10280119449600, 71960836147200, 2086864248268800, 64692791696332800, 582235125266995200, 21542699634878822400, 883250685030031718400, 37979779456291363891200, 189898897281456819456000

Offset: 1

Author

J. Lowell, Feb 04 2022

Keywords

• nonn

Comments

Similar sequences starting with smaller powers of 2 are known to converge after a few terms.

This sequence is constant from n = 35. I.e.: a(n) = a(35) for all n >= 36. - Daniel Suteu, Mar 15 2022

Examples

			2048 has 12 divisors. LCM of 2048 and 60 (smallest number with 12 divisors) is 30720.
		

Links

• Daniel Suteu, Table of n, a(n) for n = 1..36
• Daniel Suteu, Perl program

Crossrefs

Cf. A140635.

Programs

Mathematica

f[n_] := Module[{d = DivisorSigma[0, n], k = 1}, While[DivisorSigma[0, k] != d, k++]; k]; a[1] = 2048; a[n_] := a[n] = LCM[a[n - 1], f[a[n - 1]]]; Array[a, 5] (* Amiram Eldar, Feb 04 2022 *)

Extensions

a(5)-a(7) from Amiram Eldar, Feb 04 2022

a(8)-a(17) from Jon E. Schoenfield and Daniel Suteu, Mar 15 2022