A082768 Numbers that begin with 1, 3, 7 or 9.

1, 3, 7, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119

Offset: 1

Author

Amarnath Murthy, Apr 18 2003

Keywords

• base
• easy
• nonn
• changed

Crossrefs

Cf. A082769, A082770, A045572 (Numbers that end with 1, 3, 7 or 9).

Cf. A082769, A082770, A089743.

Programs

Maple

isA082768 := proc(n)
    convert(n,base,10) ;
    if op(-1,%) in {1,3,7,9} then
        true;
    else
        false;
    end if;
end proc:
A082768 := proc(n)
    if n = 1 then
        1;
    else
        for a from procname(n-1)+ 1 do
            if isA082768(a) then
                return a;
            end if;
        end do:
    end if;
end proc:
seq(A082768(n),n=1..120) ; # R. J. Mathar, Aug 27 2025

Mathematica

Select[Range[119], MemberQ[{1, 3, 7, 9}, First[IntegerDigits[#]]] &] (* Jayanta Basu, Jun 24 2013 *)

Extensions

More terms from David Wasserman, Jul 28 2005

Offset changed by Andrew Howroyd, Sep 29 2024