OFFSET
1,2
REFERENCES
I. G. MacDonald, On the degrees of the irreducible representations of symmetric groups, Bull. London Math. Soc. 3 (1971), 189-192
LINKS
Eric M. Schmidt, Table of n, a(n) for n = 1..1000
FORMULA
If n = sum a_i*3^e[i] in base 3 where a_i is 0, 1, 2 then a(n) = product g(i) where if a(i) = 0 g(i) = 1, if a(i) = 1 g(i) = 3^i, if a(i) = 2 g(i) = 3^i * (3^i + 3) / 2
EXAMPLE
a(4) = 3 because the degrees for S_4 are 1,1,2,3,3 and by the formula: 4 in base 3 is 11 and a(4) = 1*3
MATHEMATICA
a[n_] := (id = IntegerDigits[n, 3]; lg = Length[id]; Times @@ Table[ Which[ id[[lg-i]] == 0, 1, id[[lg-i]] == 1, 3^i, True, 3^i*(3^i+3)/2], {i, lg-1, 0, -1}]); Table[a[n], {n, 1, 56}] (* Jean-François Alcover, Apr 30 2013 *)
PROG
(Sage)
def A060840(n) : dig = n.digits(3); return prod([1, 3^m, 3^m*(3^m+3)//2][dig[m]] for m in range(len(dig)))
# Eric M. Schmidt, Apr 30 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Noam Katz (noamkj(AT)hotmail.com), May 02 2001
EXTENSIONS
More terms from Larry Reeves (larryr(AT)acm.org), May 10 2001
STATUS
approved