A261642 - OEIS

A261642

Triangle, read by rows, where T(n,k) = (k^2 + k)^(n-k) for k=1..n and n>=1.

1, 2, 1, 4, 6, 1, 8, 36, 12, 1, 16, 216, 144, 20, 1, 32, 1296, 1728, 400, 30, 1, 64, 7776, 20736, 8000, 900, 42, 1, 128, 46656, 248832, 160000, 27000, 1764, 56, 1, 256, 279936, 2985984, 3200000, 810000, 74088, 3136, 72, 1, 512, 1679616, 35831808, 64000000, 24300000, 3111696, 175616, 5184, 90, 1

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OFFSET

1,2

COMMENTS

Matrix inverse of triangle P with element P(n,k) = (-1)^(n-k) * (k^2 + k)^(n-k) / (n-k)! forms triangle A103244.

LINKS

Table of n, a(n) for n=1..55.

EXAMPLE

This triangle begins:

2, 1;

4, 6, 1;

8, 36, 12, 1;

16, 216, 144, 20, 1;

32, 1296, 1728, 400, 30, 1;

64, 7776, 20736, 8000, 900, 42, 1;

128, 46656, 248832, 160000, 27000, 1764, 56, 1;

256, 279936, 2985984, 3200000, 810000, 74088, 3136, 72, 1;

512, 1679616, 35831808, 64000000, 24300000, 3111696, 175616, 5184, 90, 1;

1024, 10077696, 429981696, 1280000000, 729000000, 130691232, 9834496, 373248, 8100, 110, 1; ...

PROG

(PARI) {T(n, k) = (k^2 + k)^(n-k)}

for(n=1, 10, for(k=1, n, print1(T(n, k), ", ")); print(""))

CROSSREFS

Cf. A103244, A261643 (row sums).

Sequence in context: A346905 A075497 A158983 * A185947 A268472 A079474

Adjacent sequences: A261639 A261640 A261641 * A261643 A261644 A261645

KEYWORD

nonn,tabl

AUTHOR

Paul D. Hanna, Aug 27 2015

STATUS

approved