A175091 Numbers k such that A074753(k) == (2,4) (mod 6).

4, 7, 13, 15, 21, 22, 23, 24, 40, 49, 50, 51, 52, 53, 54, 57, 64, 65, 66, 67, 68, 73, 74, 79, 80, 94, 95, 96, 99, 100, 101, 102, 111, 112, 122, 123, 124, 127, 134, 135, 136, 137, 138, 145, 146, 147, 148, 149, 150, 159, 160, 172, 173, 174, 177, 178, 179, 180, 181, 182

Offset: 1

Author

Giovanni Teofilatto, Jan 29 2010

Keywords

• nonn

Crossrefs

Cf. A074753.

Programs

Maple

A074753 := proc(n) option remember ; local a,k ; a := 0 ; for k from 1 to n do if numtheory[sigma](k) < n then a := a+1 ; end if; end do ; a ; end proc: isA175091 := proc(n) return ( (A074753(n) mod 6 )in {2,4}) ; end proc ; for n from 1 to 300 do if isA175091(n) then printf("%d,",n) ; end if; end do ; # R. J. Mathar, Feb 08 2010

Extensions

Corrected by R. J. Mathar, Feb 08 2010