login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A113762 Numbers n with nonzero digits in their decimal representation such that when all numbers formed by inserting the exponentiation symbol between any two digits are added up, the sum is prime. 1

%I

%S 21,31,51,71,121,142,161,162,164,181,211,237,326,343,412,416,456,491,

%T 494,612,616,726,817,929,1226,1228,1427,1513,1622,1776,1824,1828,1911,

%U 1915,1975,2127,2188,3716,5265,6276,6321,6491,6852,7739,14423,14487

%N Numbers n with nonzero digits in their decimal representation such that when all numbers formed by inserting the exponentiation symbol between any two digits are added up, the sum is prime.

%e a(6) = 142 because 1^42+14^2 = 197, which is prime.

%t lst = {}; Do[ If[ Min@ IntegerDigits@n > 0, a=0; p=10; While[(w = Floor[n/p]) > 0, a += w^ Mod[n, p]; p*=10]; If[PrimeQ[a], Print[{n, a}]; AppendTo[lst, n]]], {n, 11, 9999}]; lst

%Y Cf. A117388.

%K base,nonn

%O 1,1

%A _Ray G. Opao_, Jan 18 2006

%E More terms from _Giovanni Resta_, Jan 19 2006

%E More terms from _Robert G. Wilson v_, Apr 27 2006

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 19 00:40 EST 2020. Contains 331030 sequences. (Running on oeis4.)