A161226 a(0)=0. a(n) = the smallest integer of the form k^j, j>=2, such that a(n) >= a(n-1) + n.

0, 1, 4, 8, 16, 25, 32, 49, 64, 81, 100, 121, 144, 169, 196, 216, 243, 289, 324, 343, 400, 441, 484, 512, 576, 625, 676, 729, 784, 841, 900, 961, 1000, 1089, 1156, 1225, 1296, 1369, 1444, 1521, 1600, 1681, 1728, 1849, 1936, 2025, 2116, 2187, 2304, 2401, 2500

Offset

0,3

Links

Table of n, a(n) for n=0..50.

Mathematica

fQ[n_] := GCD @@ Last /@ FactorInteger@n > 1; f[n_] := f[n] = Block[{k = f[n - 1] + n}, While[ !fQ@k, k++ ]; k]; f[0] = 0; f[1] = 1; Table[ f@n, {n, 0, 50}] (* Robert G. Wilson v, Jun 09 2009 *)

Prog

(Magma) P:=[1] cat [ n: n in [2..2500] | IsPower(n) ]; S:=[0]; p:=1; n:=1; while p le #P do if P[p] ge (S[ #S]+n) then Append(~S, P[p]); n+:=1; end if; p+:=1; end while; S; // Klaus Brockhaus, Jun 10 2009

Crossrefs

Cf. A001597.

Cf. A001597 (perfect powers: m^k where m is an integer and k >= 2). - Klaus Brockhaus, Jun 10 2009

Sequence in context: A368614 A330992 A246067 * A369566 A022560 A290190

Adjacent sequences: A161223 A161224 A161225 * A161227 A161228 A161229

Keyword

nonn

Author

Leroy Quet, Jun 06 2009

Extensions

Extended by Ray Chandler, Klaus Brockhaus and Robert G. Wilson v, Jun 11 2009

Status

approved