# A355827 for range 1 .. 65537 computed by Antti Karttunen, 2022-07-19 # in GP/PARI CALCULATOR Version 2.9.4 (released) amd64 running linux (x86-64/GMP-6.1.2 kernel) 64-bit version, compiled: Dec 19 2017, gcc version 7.3.0 (Ubuntu 7.3.0-1ubuntu1), threading engine: pthread # with the following program: # # ispow2(n) = (n && !bitand(n,n-1)); # A302777(n) = ispow2(isprimepower(n)); # memoA355827 = Map(); # A355827(n) = if(1==n,1,my(v); if(mapisdefined(memoA355827,n,&v), v, v = -sumdiv(n,d,if(d