The meicosillion is equal to \(10^{3\left(10^{63}\right)+3}\) or \(10^{3\text{ vigintillion }3}\).[1] The term was coined by Aarex Tiaokhiao.
Approximations
| Notation | Lower bound | Upper bound |
|---|---|---|
| Arrow notation | \(1000\uparrow(1+10\uparrow63)\) | |
| Down-arrow notation | \(1000\downarrow\downarrow22\) | \(551\downarrow\downarrow24\) |
| Steinhaus-Moser Notation | 38[3][3] | 39[3][3] |
| Copy notation | 2[2[64]] | 3[3[64]] |
| H* function | H(H(20)) | |
| Taro's multivariable Ackermann function | A(3,A(3,209)) | A(3,A(3,210)) |
| Pound-Star Notation | #*((1))*(11,6)*14 | #*((1))*(6,2,1,1,1)*5 |
| BEAF | {1000,1+{10,63}} | |
| Hyper-E notation | E(3+3E63) | |
| Bashicu matrix system | (0)(1)[14] | (0)(1)[15] |
| Hyperfactorial array notation | (48!)! | (49!)! |
| Fast-growing hierarchy | \(f_2(f_2(204))\) | \(f_2(f_2(205))\) |
| Hardy hierarchy | \(H_{\omega^22}(204)\) | \(H_{\omega^22}(205)\) |
| Slow-growing hierarchy | \(g_{\omega^{\omega^{\omega6+3}3+3}}(10)\) | |