Unicode "Math double-struck" :
𝔸𝔹ℂ𝔻 𝔼𝔽𝔾ℍ 𝕀𝕁𝕂𝕃 𝕄ℕ𝕆ℙ ℚℝ𝕊𝕋 𝕌𝕍𝕎𝕏 𝕐ℤ ~ 𝕒𝕓𝕔𝕕 𝕖𝕗𝕘𝕙 𝕚𝕛𝕜𝕝 𝕞𝕟𝕠𝕡 𝕢𝕣𝕤𝕥 𝕦𝕧𝕨𝕩 𝕪𝕫 ~ 𝟘𝟙𝟚𝟛𝟜𝟝𝟞𝟟𝟠𝟡 ~ 𝕊𝕚𝕟𝕕 𝕊𝔼ℝℙ 𝕋𝕚𝕥𝕝𝕖𝕤 𝕦𝕟𝕕 𝔻𝕖𝕤𝕔𝕣𝕚𝕡𝕥𝕚𝕠𝕟𝕤 𝕚𝕟 𝕌𝕟𝕚𝕔𝕠𝕕𝕖 𝕤𝕚𝕟𝕟𝕧𝕠𝕝𝕝 𝕗𝕦𝕖𝕣 𝕊𝔼𝕆 𝕦𝕟𝕕 𝕖𝕣𝕙𝕠𝕖𝕙𝕖𝕟 𝕒𝕝𝕤 𝔼𝕪𝕖 ℂ𝕒𝕥𝕔𝕙𝕖𝕣 𝕕𝕚𝕖 ℂ𝕋ℝ 𝕠𝕕𝕖𝕣 𝕨𝕖𝕣𝕕𝕖𝕟 𝕤𝕚𝕖 𝕧𝕠𝕞 𝕌𝕤𝕖𝕣 𝕖𝕙𝕖𝕣 𝕒𝕝𝕤 𝕤𝕡𝕒𝕞𝕞𝕪 𝕨𝕒𝕙𝕣𝕘𝕖𝕟𝕠𝕞𝕞𝕖𝕟 𝕦𝕟𝕕 𝕤𝕠 𝕟𝕖𝕘𝕒𝕥𝕚𝕧 𝕗𝕦𝕖𝕣 𝕊𝔼𝕆?