A038315 Triangle whose (i,j)-th entry is binomial(i,j)*11^(i-j)*1^j.

1, 11, 1, 121, 22, 1, 1331, 363, 33, 1, 14641, 5324, 726, 44, 1, 161051, 73205, 13310, 1210, 55, 1, 1771561, 966306, 219615, 26620, 1815, 66, 1, 19487171, 12400927, 3382071, 512435, 46585, 2541, 77, 1, 214358881, 155897368, 49603708

Offset

0,2

Comments

T(i,j) is the number of i-permutations of 12 objects a,b,c,d,e,f,g,h,i,j,k,l, with repetition allowed, containing j a's. - Zerinvary Lajos, Dec 21 2007

References

B. N. Cyvin et al., Isomer enumeration of unbranched catacondensed polygonal systems with pentagons and heptagons, Match, No. 34 (Oct 1996), pp. 109-121.

Links

Table of n, a(n) for n=0..38.

Example

1
11, 1
121, 22, 1
1331, 363, 33, 1
14641, 5324, 726, 44, 1
161051, 73205, 13310, 1210, 55, 1
1771561, 966306, 219615, 26620, 1815, 66, 1
19487171, 12400927, 3382071, 512435, 46585, 2541, 77, 1
214358881, 155897368, 49603708, 9018856, 1024870, 74536, 3388, 88, 1

Maple

for i from 0 to 8 do seq(binomial(i, j)*11^(i-j), j = 0 .. i) od; # Zerinvary Lajos, Dec 21 2007

Mathematica

Table[Binomial[i, j]11^(i-j), {i, 0, 10}, {j, 0, i}]//Flatten (* Harvey P. Dale, Nov 10 2022 *)

Crossrefs

Sequence in context: A281523 A282420 A282683 * A218018 A093158 A335157

Adjacent sequences: A038312 A038313 A038314 * A038316 A038317 A038318

Keyword

nonn,tabl,easy

Author

N. J. A. Sloane

Status

approved