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A274401 Number of balanced linear 4-partitions of the n X n grid. 1
0, 1, 8, 3, 16, 7, 32, 13, 48, 19, 80, 29, 96, 41, 144, 49, 176, 65, 224, 83, 256, 95, 336, 117, 368, 137, 464, 155, 512, 183, 576, 213, 640, 233, 768, 257, 816, 293, 960, 317, 1024, 357, 1120, 399, 1200, 423, 1376, 469, 1440 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..49.

D. M. Acketa, N. Divljak, J. Zunic. On balanced linear 4-partitions of the (n,n)-grid. Novi Sad Journal of Mathematics 24:1 (1994), 309-319.

FORMULA

For odd n, a(n) = 8 * A002088((n-1)/2).

For even n, a(n) = A099957(n/2).

PROG

(PARI) { a(n) = if(n%2, 8*sum(m=1, (n-1)\2, eulerphi(m)), sum(m=0, (n-1)\2, eulerphi(2*m+1)) ); }

CROSSREFS

Cf. A002088, A099957.

Sequence in context: A070486 A195161 A144433 * A228691 A228313 A037206

Adjacent sequences:  A274398 A274399 A274400 * A274402 A274403 A274404

KEYWORD

nonn,easy

AUTHOR

Max Alekseyev, Jun 20 2016

STATUS

approved

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Last modified August 22 00:43 EDT 2019. Contains 326169 sequences. (Running on oeis4.)