A056235 a(n) = n*2^(n*2^n+n)-1.

7, 2047, 402653183, 1180591620717411303423, 233840261972944466912589573234605283144949206876159

Offset

1,1

Comments

For n>2, a(n) is base at which zero is reached for the function "write f(j) in base j, read as base j+1 and then subtract 1 to give f(j+1)" starting from f(n) = 2n^2-1.

Links

Table of n, a(n) for n=1..5.

Formula

a(n) = A003261(A036289(n)) = A036289(n)*A001146(n)^n-1.

Example

a(3) = 3*2^(3*2^3+3)-1 = 3*2^27-1 = 402653184-1 = 402653183.

Mathematica

Table[n 2^(n 2^n+n)-1, {n, 5}] (* Harvey P. Dale, Dec 24 2025 *)

Crossrefs

Cf. A001146, A003261, A036289.

Sequence in context: A145253 A248730 A024099 * A139299 A004818 A125538

Adjacent sequences: A056232 A056233 A056234 * A056236 A056237 A056238

Keyword

nonn

Author

Henry Bottomley, Aug 06 2000

Status

approved