OFFSET
0,5
LINKS
T. D. Noe, Rows n = 0..100 of triangle, flattened
FORMULA
T(n, k) = sigma(binomial(n, k)) (0 <= k <= n).
EXAMPLE
T(6,3)=42 because the sum of the divisors of binomial(6,3)=20 is 1+2+4+5+10+20=42.
Triangle begins:
1;
1, 1;
1, 3, 1;
1, 4, 4, 1;
1, 7, 12, 7, 1;
MAPLE
with(numtheory): T:=(n, k)->sigma(binomial(n, k)): for n from 0 to 11 do seq(T(n, k), k=0..n) od; # yields sequence in triangular form
MATHEMATICA
Table[DivisorSigma[1, Binomial[n, k]], {n, 0, 20}, {k, 0, n}]//Flatten (* Harvey P. Dale, Mar 25 2016 *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Emeric Deutsch, Feb 06 2005
STATUS
approved