Bash, ^{139 . . . 113} 104 bytes

_()($[a=b=1];for n in `seq $1`;{ printf "%${s}s";echo -n $a+$b;$[c=a+b,s+=${#a}+1,a=b,b=c];echo "=$c";}) 

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Bash, ^{139 . . . 104} 103 bytes

_()($[a=b=1];for n in `seq $1`;{ printf "%${s}s";echo -n $a+$b;$[c=a+b,s+=~${#a},a=b,b=c];echo "=$c";}) 

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Bash, ^{139 . . . 117} 113 bytes

_()($[s=a=b=1];for n in `seq $1`;{ printf ' %.s' `seq $s`;echo -n $a+$b;$[c=a+b,s+=${#a}+1,a=b,b=c];echo "=$c";}) 

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Bash, ^{139 . . . 113} 104 bytes

_()($[a=b=1];for n in `seq $1`;{ printf "%${s}s";echo -n $a+$b;$[c=a+b,s+=${#a}+1,a=b,b=c];echo "=$c";}) 

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Bash, ^{139 . . . 119}   117 bytes

_(){ s=1;a=1;b=1;for n in `seq $1`;{ printf ' %.s' `seq $s`;echo -n $a+$b;((c=a+b,s+=${#a}+1,a=b,b=c));echo "=$c";} } 

-10 bytes without some whitespaces
-4 bytes without c=1 statement
-6 bytes without last let statement
-2 bytes without let

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Bash, ^{139 . . . 117} 113 bytes

_()($[s=a=b=1];for n in `seq $1`;{ printf ' %.s' `seq $s`;echo -n $a+$b;$[c=a+b,s+=${#a}+1,a=b,b=c];echo "=$c";}) 

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