ATtiny45 & 85 Pin Output Question

[unor3man]

Hi. I have a sketch that I downloaded to an ATtiny45 to trigger a sequence of 5 LEDs, but for some reason, the output of pin 2 (assigned to LED #3) from the tiny is dim. In fact, it's only 2.5V, and it should be 5V. However, when I assign pin 3 to LEDs #3 and #4, the result is perfect, and bright. Can someone explain why this happens? Thanks so much! Here is the sketch:

int Led1 = 0;
int Led2 = 1;
int Led3 = 2;
int Led4 = 3;
int Led5 = 4;

void  setup(){
pinMode (Led1, 5);
pinMode (Led5, 6);
pinMode (Led2, 7);
pinMode (Led3, 3);
pinMode (Led4, 3);
}

void loop(){
digitalWrite (Led1, HIGH);
delay (75);
digitalWrite (Led1, LOW);
delay (75);
digitalWrite (Led1, HIGH);
delay (75);
digitalWrite (Led1, LOW);
delay (75);
delay (200);

digitalWrite (Led2, HIGH);
delay (75);
digitalWrite (Led2, LOW);
delay (75);
digitalWrite (Led2, HIGH);
delay (75);
digitalWrite (Led2, LOW);
delay (75);
delay (200);

digitalWrite (Led3, HIGH);
delay (75);
digitalWrite (Led3, LOW);
delay (75);
digitalWrite (Led3, HIGH);
delay (75);
digitalWrite (Led3, LOW);
delay (75);
delay (200);

digitalWrite (Led4, HIGH);
delay (75);
digitalWrite (Led4, LOW);
delay (75);
digitalWrite (Led4, HIGH);
delay (75);
digitalWrite (Led4, LOW);
delay (75);
delay (200);

digitalWrite (Led5, HIGH);
delay (75);
digitalWrite (Led5, LOW);
delay (75);
digitalWrite (Led5, HIGH);
delay (75);
digitalWrite (Led5, LOW);
delay (75);
delay (200);
}

[CrossRoads]

Shouldn't these be like this?

void  setup(){
pinMode (Led1, OUTPUT);
pinMode (Led5, OUTPUT);
pinMode (Led2, OUTPUT);
pinMode (Led3, OUTPUT);
pinMode (Led4, OUTPUT);
}

[unor3man]

Wow, CrossRoads. You know what? That was it! I'm so happy. I replaced my bizarre setup (which was modified from a YT video) with yours, and it works perfectly! Mystery solved. Thank you very much!

[PaulRB]

I'm curious. Why was the value 3 treaded as OUTPUT for Led4/pin 3 but not for Led3/pin 2?

[DrAzzy]

I think he is getting the pin and led numbers mixed up,. nearly did while trying to respond,. A set of leds 1 number off from their pin numbers is a recipe for confusion.

I'm also not sure what core he's using, heh. unknown values default to,.... OUTPUT?! Am I reading the code right? I'd have gone with INPUT but that is how the official core does it, and how ATTinyCore does it because it's based on that.