The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A046273 Largest prime substring in 7^n (0 if none). 3
 0, 7, 0, 43, 401, 7, 7649, 823, 4801, 3607, 82475249, 7326743, 41287201, 89, 23072849, 7561, 232930569601, 2630513987207, 8413597910449, 398895185373143, 297612001, 558545864083, 2988049, 3400809163 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..200 MATHEMATICA lpss[n_]:=Module[{idn7=IntegerDigits[7^n]}, Max[Select[Flatten[ Table[ FromDigits/@ Partition[idn7, i, 1], {i, Length[idn7]}]], PrimeQ]]]; Array[ lpss, 25, 0]/.-\[Infinity]->0 (* Harvey P. Dale, Aug 17 2013 *) CROSSREFS Cf. A046265. Sequence in context: A157779 A222322 A228762 * A167317 A266436 A240822 Adjacent sequences:  A046270 A046271 A046272 * A046274 A046275 A046276 KEYWORD nonn AUTHOR Patrick De Geest, Jun 15 1998 STATUS approved

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.

Last modified January 21 11:28 EST 2022. Contains 350477 sequences. (Running on oeis4.)