A271577 Powers, squares excepted, of the form x^2+y^4, with x,y > 0 (see A111925).

32, 512, 2197, 3125, 8000, 8192, 15625, 64000, 100000, 131072, 1419857, 1953125, 2097152, 3200000, 7189057, 8000000, 8998912, 9765625, 11390625, 11881376, 30664297, 32768000, 33554432, 35287552, 62748517, 64000000, 69343957, 115856201, 125000000, 221445125, 262144000, 272097792

Offset

1,1

Links

Chai Wah Wu, Table of n, a(n) for n = 1..1255

Example

32 = 2^5 = 16 + 16 = 2^2 + 2^4, so 32 is a term.

Prog

(PARI) isok(n) = {if ((p=ispower(n)) && (p != 2), for (k=1, n-1, if (issquare(k) && (p=ispower(n-k, 4)), return (1)); ); ); }

Crossrefs

Cf. A111925, A271576.

Sequence in context: A238534 A297091 A371453 * A116003 A035711 A035477

Adjacent sequences: A271574 A271575 A271576 * A271578 A271579 A271580

Keyword

nonn

Author

Michel Marcus, Apr 10 2016

Status

approved