は锣计
癴计
癴计 (Reversible Prime) 嘿は计 (Emirp) 硂琌ぐ或㎡ウ璣ゅ会禣秆ㄥтぃ秆睦砛Τ琌瓣ゅ砛Τ硂㎝ Emir (甁μ焊 - 縫吹狶癸参獀碙嘿) ┪ Emirate (甁μ焊烈) Τ闽иぃ礛
ㄓ Emirp 琌р璣ゅ Prime (计) は筁ㄓ (Reversal) ﹃τΘ璝计は筁ㄓ琌计硂獽琌癴计┪は计
孔は筁ㄓ 13 => 31 149 => 941 单獽琌иノ计厩﹚竡ぃ糶ㄢㄒㄓ┪フ讽礛腨ㄓ弧琌ㄧ计砞计 p = an10n + an-110n-1 + ...... + a0 ㄤい ai 0 - 9 ぇ丁俱计
τ f(p) = a010n + a110n-1 + ...... + an
璝 f(p) 琌计p 獽琌は计ㄤ龟 f(p) 穦琌は计
礛10111 单ゅ计 (Palindromic Prime) ゲ礛は锣は锣琌计ирウ埃癴计﹚竡滦ぇ尔パ癴计ゲ礛琌蛮癸瞷 13 ㎝ 31 149 ㎝ 941 单
ê或иㄇ计琌癴计㎡
13, 17, 31, 37, 71, 73, 79, 97, 107, 113, 149, 157, ... (OEIS A006567)
癴计
瞶癴计 (Reversible Semiprime) 嘿は计 (Emirpimes) 硂琌は锣计琌计计璣ゅ Emirpimes 琌眖 Semiprime (计) いは筁ㄓ﹃τΘㄤい计琌计度パㄢ计τㄓ冈ǎぃ琌计琾计ゅ讽礛癴计ョぃ珹 121 单ゅ计 (Palindromic Semiprime) 珿硂癴计琌蛮癸ǐи泊玡
は计ㄒ15, 26, 39, 49, 51, 58, 62, 85, 93, 94, 115, 122, 123, ... (OEIS A097393)
и╯癴计だ眔
n |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
10n ず癴计计ヘ |
0 |
10 |
90 |
898 |
7200 |
60732 |
506724 |
徽Τぐ或稰谋и癴计だ琌禫ㄓ禫祡波
Emirp ㎝ Prime ┪ Emirpimes 琌眖 Semiprime ㄢ癸и稱癬硂砛琌璣ゅ单パダ舱Θゅ砰╰贺よ遏舱Θ迭粂いゅ砰╰い硂玱︽ぃ硄ぃ礛и计┪计痷ぃ穦琌ぐ或狥﹁
把σゅ膍の呼
Gardner, M. The Magic Numbers of Dr Matrix. Buffalo, New York : Prometheus, p. 230, 1985.
Rivera, C. "Problems & Puzzles: Puzzle 020-Reversible Primes." http://www.primepuzzles.net/puzzles/puzz_020.htm.
Weisstein, E. W. "Emirp." From MathWorld. http://mathworld.wolfram.com/Emirp.html.
Weisstein, E. W. "Emirpimes." From MathWorld. http://mathworld.wolfram.com/Emirpimes.html.