OFFSET
1,3
LINKS
B. D. Swan, Table of n, a(n) for n = 1..10000
MAPLE
A000326 := proc(n) n*(3*n-1)/2 ; end: A000203 := proc(n) numtheory[sigma](n) ; end: A000005 := proc(n) numtheory[tau](n) ; end: A152770 := proc(n) A000203(n)-A000005(n)-n+1 ; end: A152986 := proc(n) A152770(A000326(n)) ; end: for n from 1 to 80 do printf("%a, ", A152986(n)) ; od: # R. J. Mathar, Jan 03 2009
MATHEMATICA
DivisorSigma[1, #]-#-DivisorSigma[0, #]+1&/@PolygonalNumber[5, Range[60]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 02 2021 *)
CROSSREFS
KEYWORD
AUTHOR
Omar E. Pol, Dec 22 2008
EXTENSIONS
Extended by R. J. Mathar, Jan 03 2009
STATUS
approved