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A320728 Numbers that are sums of consecutive odd squares (or centered octagonal numbers). 5
0, 1, 9, 10, 25, 34, 35, 49, 74, 81, 83, 84, 121, 130, 155, 164, 165, 169, 202, 225, 251, 276, 285, 286, 289, 290, 361, 371, 394, 420, 441, 445, 454, 455, 514, 515, 529, 596, 625, 645, 650, 670, 679, 680, 683, 729, 802, 804, 841, 875, 885, 934, 959, 961, 968, 969, 970, 1044, 1089 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..59.

Index entries for sequences related to sums of squares

PROG

(PARI) ok(n)={my(i=sqrtint(n)); i=i-(i%2==0); while(i>0, my(a=i^2, j=i); while(j>0 && a<=n, if(a==n, return(1)); j-=2; a=a+j^2); i-=2); 0}

concat([0], select(ok, [1..1200])) \\ Antonio Roldán, Mar 12 2020

CROSSREFS

Cf. A000447, A016754, A034705, A152043, A322610, A322611, A322637, A322638, A322640.

Sequence in context: A290275 A156787 A025043 * A111033 A123048 A189047

Adjacent sequences:  A320725 A320726 A320727 * A320729 A320730 A320731

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Dec 21 2018

STATUS

approved

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Last modified September 19 11:23 EDT 2021. Contains 347556 sequences. (Running on oeis4.)