Re: Error: Prime::intpp: Positive integer argument expected in Prime[16.`]
- To: mathgroup at smc.vnet.net
- Subject: [mg61913] Re: Error: Prime::intpp: Positive integer argument expected in Prime[16.`]
- From: "antononcube" <antononcube at gmail.com>
- Date: Fri, 4 Nov 2005 05:11:38 -0500 (EST)
- References: <dk6vtg$gi1$1@smc.vnet.net><dk9vvh$6tm$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Sum cannot evaluate the summand it is given, so NSum is used. Here is way to check that NSum gives reliable results: (V6.0) In[113]:= exact=Total@Table[1/2^Prime[n],{n,1,10}] %//N//InputForm (V6.0) Out[113]= 222630977/536870912 (V6.0) Out[114]//InputForm= 0.41468250937759876 (V6.0) In[107]:= NSum[1/2^Prime[n],{n,1,\[Infinity]}] NSum[1/2^Prime[n],{n,11,\[Infinity]}] res=%%-%; res//InputForm During evaluation of (V6.0) In[107]:= Prime::"intpp": "Positive integer argument expected in Prime[16.]." During evaluation of (V6.0) In[107]:= Prime::"intpp": "Positive integer argument expected in Prime[17.]." During evaluation of (V6.0) In[107]:= Prime::"intpp": "Positive integer argument expected in Prime[18.]." During evaluation of (V6.0) In[107]:= General::"stop": "Further output of Prime::"intpp" will be suppressed during \ this calculation." (V6.0) Out[107]= 0.414683 During evaluation of (V6.0) In[107]:= Prime::"intpp": "Positive integer argument expected in Prime[26.]." During evaluation of (V6.0) In[107]:= Prime::"intpp": "Positive integer argument expected in Prime[27.]." During evaluation of (V6.0) In[107]:= Prime::"intpp": "Positive integer argument expected in Prime[28.]." During evaluation of (V6.0) In[107]:= General::"stop": "Further output of Prime::"intpp" will be suppressed during \ this calculation." (V6.0) Out[108]= 4.73513×10^(-10) (V6.0) Out[110]//InputForm= 0.41468250937759876 (V6.0) In[112]:= exact-res//InputForm (V6.0) Out[112]//InputForm= 0.