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A212015 Nonsquare positive integers that are sums of consecutive integer squares. 4
2, 5, 6, 10, 13, 14, 15, 19, 28, 29, 30, 31, 35, 41, 44, 50, 54, 55, 56, 60, 61, 69, 77, 85, 86, 90, 91, 92, 96, 105, 110, 113, 126, 135, 139, 140, 141, 145, 146, 149, 154, 170, 174, 181, 182, 190, 194, 195, 199, 203, 204, 205, 209, 218, 221, 230, 231 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Nonsquare terms of A062861.

Subsequence of A212016.

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

MAPLE

filter:= proc(n)

  not issqr(n) and

  ormap(k -> issqr(-3*k^4+3*k^2+36*k*n) and  ((3*k-3*k^2+sqrt(-3*k^4+3*k^2+36*k*n))/(6*k))::integer,

    numtheory:-divisors(6*n))

end proc:

select(filter, [$1..1000]); # Robert Israel, Jan 22 2017

CROSSREFS

Cf. A062861, A212016.

Sequence in context: A187231 A162340 A212016 * A255341 A089269 A047440

Adjacent sequences:  A212012 A212013 A212014 * A212016 A212017 A212018

KEYWORD

nonn

AUTHOR

Max Alekseyev, Apr 26 2012

STATUS

approved

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Last modified May 26 07:44 EDT 2019. Contains 323579 sequences. (Running on oeis4.)