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A109678 Sequence and first differences include all square numbers exactly once. 0
1, 5, 14, 30, 55, 91, 140, 204, 285, 385, 506, 650, 819, 1015, 1240, 1496, 1785, 2109, 2470, 2870, 3311, 3795, 4324, 4900, 5525, 6201, 6930, 7714, 8555, 9455, 10416, 11440, 12529, 13685, 14910, 16206, 17575, 19019, 20540, 22140, 23821, 25585 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

This sequence diverges from A000330 as 4900 (which is 70^2) appears in the sequence itself - thus won't be added to any a(n).

EXAMPLE

Superpose sequence and first differences:

1 5 14 30 55 91 140 204 285 385 506 650 819 1015

.4.9..16..25..36..49...64...81...100...121...144...169...196

All square numbers appear once and only once, either in the sequence itself or in the first differences.

MAPLE

seq(sum ((k+1)^2, k=0..n), n=0..41); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 10 2007

MATHEMATICA

s = 1; lst = {s}; Do[s += n^2; AppendTo[lst, s], {n, 2, 42, 1}]; lst [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jul 12 2009]

CROSSREFS

Sequence in context: A136135 A096893 A074784 * A000330 A166068 A070129

Adjacent sequences:  A109675 A109676 A109677 * A109679 A109680 A109681

KEYWORD

base,easy,nonn

AUTHOR

Eric Angelini (eric.angelini(AT)kntv.be), Aug 30 2005

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Last modified February 14 13:08 EST 2012. Contains 205623 sequences.