A243093 Least number k > n such that n concatenated with k is a perfect power.

6, 5, 6, 9, 12, 25, 29, 41, 61, 24, 56, 25, 31, 44, 21, 81, 28, 49, 36, 25, 87, 201, 104, 336, 281, 244, 44, 224, 241, 276, 36, 49, 64, 81, 344, 100, 249, 44, 69, 96, 209, 436, 56, 89, 369, 225, 61, 400, 284, 176, 84, 441, 361, 76, 225, 169, 76, 564, 319, 84, 504, 500, 504, 516, 536, 564

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Mathematica

pp[n_]:=Module[{k=n+1}, While[GCD@@FactorInteger[n*10^IntegerLength[ k]+ k][[All, 2]]<2, k++]; k]; Array[pp, 70] (* Harvey P. Dale, Oct 09 2016 *)

Prog

(PARI)
a(n)=s=Str(n); k=n+1; while(!ispower(eval(concat(s, Str(k)))), k++); return(k)
vector(100, n, a(n))
(Python)
from sympy import perfect_power
def a(n):
    s, k = str(n), n+1
    while not perfect_power(int(s+str(k))): k += 1
    return k
print([a(n) for n in range(1, 67)]) # Michael S. Branicky, Jun 05 2021

Crossrefs

Cf. A245632.

Sequence in context: A019621 A335263 A126689 * A101634 A071176 A243091

Adjacent sequences: A243090 A243091 A243092 * A243094 A243095 A243096

Keyword

nonn,base

Author

Derek Orr, Aug 18 2014

Status

approved