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A181675 V(n,n^2), where V is the number of integer points in an n-dimensional sphere of Lee-radius n^2 centered at the origin. 0
3, 41, 1159, 50049, 2908411, 212358985, 18665359119, 1917971421185, 225555471838387, 29871434052884841, 4398867465890529303, 712959801840558794625, 126115813138335816685995 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

Since V(n,d) is symmetric, we have V(n,n^2) = V(n^2,n).

REFERENCES

Solomon W. Golomb and Lloyd R. Welch, "Perfect Codes in the Lee Metric and the Packing of Polyominoes", SIAM Journal on Applied Mathematics Vol. 18, No. 2 (Mar. 1970), pp. 302-317.

LINKS

Table of n, a(n) for n=2..14.

FORMULA

V(n,d) = sum_{j=0..min(n,d)} 2^j * binomial(n,j)*binomial(d,j).

MATHEMATICA

Sum[2^j * Binomial[n, j]*Binomial[d, j], {j, 0 Min[n, d]}]

CROSSREFS

V(n, n) = A001850, V(n, 2n) = A026000 and V(n, 3n) = A026001.

Sequence in context: A007313 A222524 A241704 * A012053 A012162 A012225

Adjacent sequences:  A181672 A181673 A181674 * A181676 A181677 A181678

KEYWORD

easy,nonn

AUTHOR

Antonio Campello, Nov 04 2010

STATUS

approved

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Last modified February 20 12:57 EST 2019. Contains 320327 sequences. (Running on oeis4.)