OFFSET
1,1
LINKS
Paolo Xausa, Table of n, a(n) for n = 1..11325 (first 150 antidiagonals, flattened).
FORMULA
EXAMPLE
The top left corner of the array:
n\k| 1 2 3 4 5 6 7 8
---+--------------------------------------------------------------------------
1 | 21, 45, 69, 93, 117, 141, 165, 189, ...
2 | 21, 117, 213, 309, 405, 501, 597, 693, ...
3 | 341, 725, 1109, 1493, 1877, 2261, 2645, 3029, ...
4 | 341, 1877, 3413, 4949, 6485, 8021, 9557, 11093, ...
5 | 5461, 11605, 17749, 23893, 30037, 36181, 42325, 48469, ...
6 | 5461, 30037, 54613, 79189, 103765, 128341, 152917, 177493, ...
7 | 87381, 185685, 283989, 382293, 480597, 578901, 677205, 775509, ...
8 | 87381, 480597, 873813, 1267029, 1660245, 2053461, 2446677, 2839893, ...
...
MATHEMATICA
A371100[n_, k_] := 4^n*(6*k - 3 - 2*(-1)^n) + (4^n - 1)/3;
Table[A371100[n - k + 1, k], {n, 10}, {k, n}] (* Paolo Xausa, Apr 21 2024 *)
PROG
(PARI)
up_to = 55;
A371100sq(n, k) = 4^n*(6*k - 3 - 2*(-1)^n) + (4^n - 1)/3;
A371100list(up_to) = { my(v = vector(up_to), i=0); for(a=1, oo, for(col=1, a, i++; if(i > up_to, return(v)); v[i] = A371100sq((a-(col-1)), col))); (v); };
v371100 = A371100list(up_to);
A371100(n) = v371100[n];
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Antti Karttunen and Ali Sada, Apr 18 2024
STATUS
approved