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Search: id:A049112
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| A049112 |
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2-ranks of difference sets constructed from Glynn type I hyperovals. |
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+0
3
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| 1, 1, 3, 7, 13, 23, 45, 87, 167, 321, 619, 1193, 2299, 4431, 8541, 16463, 31733, 61167, 117903, 227265, 438067, 844401, 1627635, 3137367, 6047469, 11656871, 22469341, 43311047, 83484727, 160921985, 310187099, 597904857, 1152498667
(list; graph; listen)
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OFFSET
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1,3
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REFERENCES
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Q. Xiang, On Balanced Binary Sequences with Two-Level Autocorrelation Functions, IEEE Trans. Inform. Theory 44 (1998), 3153-3156.
R. Evans, H. D. L. Hollmann, C. Krattenthaler, Q. Xiang, Gauss Sums, Jacobi Sums, and p-Ranks of Cyclic Difference Sets, J. Combin. Theory Ser. A 87 (1999), 74-119.
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LINKS
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Supplement to "Gauss Sums, Jacobi Sums, and p-ranks ..."
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FORMULA
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G.f.: (1-x+x^2+x^3-x^4-2*x^5)/(1-2*x+x^5).
a(n+1) = a(n) + a(n-1) + a(n-2) + a(n-3) - 1, n >= 5.
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MAPLE
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L := 1, 1, 3, 7, 13: for i from 6 to 100 do l := nops([ L ]): L := L, op(l, [ L ])+op(l-1, [ L ])+op(l-2, [ L ])+op(l-3, [ L ])-1: od: [ L ];
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MATHEMATICA
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Join[ {1, 1, 3, 7}, Table[ a[ 1 ]=3; a[ 2 ]=1; a[ 3 ]=3; a[ 4 ]=7; a[ i ]=a[ i-1 ]+a[ i-2 ]+a[ i-3 ]+a[ i-4 ]-1, {i, 5, 100} ] ]
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CROSSREFS
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Cf. A001595, A049114.
Adjacent sequences: A049109 A049110 A049111 this_sequence A049113 A049114 A049115
Sequence in context: A081494 A048462 A048465 this_sequence A100720 A084898 A101302
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KEYWORD
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nonn,easy
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AUTHOR
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Christian Krattenthaler (kratt(AT)ap.univie.ac.at)
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