cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A175053 Perfect powers (members of A001597) n where the next larger perfect power is not congruent mod 2 to n.

Original entry on oeis.org

1, 8, 9, 16, 27, 36, 49, 64, 81, 100, 125, 144, 169, 216, 243, 256, 289, 324, 361, 400, 441, 512, 529, 576, 625, 676, 729, 784, 841, 900, 961, 1024, 1089, 1156, 1225, 1296, 1369, 1444, 1521, 1600, 1681, 1764, 1849, 1936, 2025, 2116, 2209, 2304, 2401, 2500
Offset: 1

Views

Author

Leroy Quet, Dec 08 2009

Keywords

Examples

			125 (125 = 5^3) and 128 (128 = 2^7) are consecutive perfect powers. Since one of these is odd and the other is even, then 125 is in this sequence.
		

Crossrefs

Programs

  • Maple
    N:= 3000:
    PP:= {1,seq(seq(i^k,i=2..floor(N^(1/k))),k=2..ilog2(N))}:
    PP:= sort(convert(PP,list)):
    PP[select(t -> PP[t+1] mod 2 <> PP[t] mod 2,[$1..nops(PP)-1])]; # Robert Israel, May 21 2025

Extensions

Extended by Ray Chandler, Dec 10 2009