# Computed 2018-03-12 in GP/PARI CALCULATOR Version 2.9.4 (released) amd64 running mingw (x86-64/GMP-6.1.2 kernel) 64-bit version, compiled: Dec 20 2017, gcc version 4.9.1 (GCC), threading engine: single # with the following PARI-program: # # A003557(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 2] = max(0,f[i, 2]-1)); factorback(f); }; \\ From A003557 # A300719(n) = -sumdiv(n,d,(d