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A057369 Numbers k that can be expressed as k = w+x = y*z with w*x = (y+z)^2 where w, x, y, and z are all positive integers. 7
16, 18, 25, 45, 50, 80, 234, 250, 261, 425, 1025, 1040, 1530, 1625, 1746, 2320, 4250, 7605, 7794, 9650, 10413, 11050, 11925, 14416, 23425, 24050, 27920, 71298, 75650, 78416, 81693, 129625, 151625, 200720, 221425, 257085, 264618, 338949, 340245, 416050, 488610 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Soumyadeep Dhar, Table of n, a(n) for n = 1..112

EXAMPLE

a(1) = 16 = 8+8 = 4*4; 8*8 = (4+4)^2.

PROG

(PARI) is(k) = fordiv(k, y, if(issquare(k^2 - 4*(y+k/y)^2), return(1))); 0; \\ Jinyuan Wang, May 01 2021

CROSSREFS

Cf. A057370, A057371, A057372, A057373, A057442.

Sequence in context: A337374 A255847 A160778 * A178110 A117100 A101848

Adjacent sequences:  A057366 A057367 A057368 * A057370 A057371 A057372

KEYWORD

nonn

AUTHOR

Naohiro Nomoto, Sep 23 2000

EXTENSIONS

More terms from Jinyuan Wang, May 01 2021

STATUS

approved

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Last modified January 20 00:45 EST 2022. Contains 350467 sequences. (Running on oeis4.)