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A228004 Prime powers p^m with m >= 2 which are not the sum of consecutive cubes. 1
4, 16, 25, 32, 49, 81, 121, 128, 169, 243, 256, 289, 361, 529, 625, 841, 961, 1024, 1369, 1681, 1849, 2048, 2187, 2209, 2401, 2809, 3125, 3481, 3721, 4489, 5041, 5329, 6241, 6561, 6889, 7921, 8192, 9409, 10201, 10609, 11449, 11881, 12769, 14641, 16129 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10137

K. S. Brown, Sum of Consecutive Nth Powers Equals an Nth Power

G. L. Honaker, Jr. and Chris Caldwell, Prime Curios! 97

EXAMPLE

9 is not in the sequence since it is equal to 1^3 + 2^3.

PROG

(MAGMA) lst:=[]; r:=26; c:=r^3; for n in [2..r] do for m in [n-1..0 by -1] do s:=((n^2+n)^2-(m^2+m)^2)/4; if s gt c then break; end if; if not s in lst then Append(~lst, s); end if; end for; end for; lst:=Sort(lst); [p: p in [2..c] | not IsPrime(p) and IsPrimePower(p) and not p in lst];

CROSSREFS

Cf. A025475, A217843.

Sequence in context: A239522 A281990 A103052 * A269157 A202303 A214937

Adjacent sequences:  A228001 A228002 A228003 * A228005 A228006 A228007

KEYWORD

nonn

AUTHOR

Arkadiusz Wesolowski, Aug 07 2013

STATUS

approved

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Last modified August 15 13:27 EDT 2020. Contains 336504 sequences. (Running on oeis4.)