A068745 - OEIS

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A068745

Number of potential flows in 4 X 4 array with integer velocities in -n..n, i.e. number of 4 X 4 arrays with adjacent elements differing by no more than n, counting arrays differing by a constant only once.

1, 690437, 1133641543, 164185416899, 6913624013061, 138190481342321, 1678843050246451, 14285299502131463, 93044501704039945, 492225938556374973, 2204710243834695807, 8617480381892283531 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,2`
	FORMULA	`Let y=2n-1; it appears that a(n) = y(2623243666y^14 + 9598591135y^12 + 17180805187y^10 + 20342655905y^8 + 17636121503y^6 + 10907793260y^4 + 3135618144*y^2 + 304819200)/81729648000. - R. H. Hardin (rhhardin(AT)att.net), Jan 01 2007`
	CROSSREFS	`2 X 2 A063496, 3 X 3 A068744, 5 X 5 A068746, 6x6 A068747, by velocity limit 1..14 A068748-A068761, solenoidal flows A068722-A068738.` `Cf. 4 X 4 this sequence (degree 44-1) with factor 2n-1 ; 3 X 3 A068744 (degree 33-1) with factor (2n-1)^2 ; 2 X 2 A063496 (degree 22-1) with factor 2n-1.` `Sequence in context: A205280 A185922 A204788 A010084 A206518 A114676` `Adjacent sequences: A068742 A068743 A068744 * A068746 A068747 A068748`
	KEYWORD	`nonn`
	AUTHOR	`R. H. Hardin (rhhardin(AT)att.net), Feb 27 2002`

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Last modified February 17 18:01 EST 2012. Contains 206061 sequences.