OFFSET
1,2
COMMENTS
Number of maximal subgroups in dihedral group of order 2n. - Eric M. Schmidt, Oct 14 2014
LINKS
Neville Holmes, Integer Sequences
FORMULA
a(n) = 1 + A008472(n).
EXAMPLE
2: 3 (1+2); 3: 4 (1+3); 4: 3 (1+2); 5: 6 (1+5); 6: 6 (1+2+3); ...
MAPLE
with(numtheory): a:=proc(n) local F: F:=convert(factorset(n), list): 1+sum(F[j], j=1..nops(F)) end: seq(a(n), n=1..90); # Emeric Deutsch, Mar 12 2005
MATHEMATICA
Rest[ Range[0, 20] CoefficientList[ Log[E, Series[(1/(1 - x)) Product[ 1/(1 - x^Prime[j]), {j, 200}], {x, 0, 20}]], x]] (* Robert G. Wilson v, Aug 16 2011 *)
Join[{1}, Array[1+Total[FactorInteger[#][[All, 1]]]&, 80, 2]] (* Harvey P. Dale, Sep 18 2022 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
W. Neville Holmes, Aug 22 2002
EXTENSIONS
Corrected and extended by Emeric Deutsch, Mar 12 2005
STATUS
approved