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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 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.)