login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A221984
Number of primes of the form (x+1)^11 - x^11 having n digits.
1
1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 0, 2, 1, 0, 0, 3, 3, 3, 6, 6, 5, 6, 5, 20, 17, 21, 29, 33, 29, 52, 67, 86, 75, 114, 120, 146, 191, 267, 291, 394, 470, 561, 652, 837, 1063, 1339, 1709, 2018, 2475, 3092, 3680, 4750, 5925, 7295, 9063, 11174, 14034, 17294, 21208
OFFSET
9,12
COMMENTS
Number of primes having n digits and equal to the difference of two consecutive eleventh powers (x+1)^11 - x^11 = 11x(x+1)(x^2+x+1)[ x(x+1)(x^2+x+1)(x^2+x+3)+1] +1 (A189055). Values of x = A211184. Sequence of number of primes having n digits and of the form (x+1)^11 - x^11 have similar characteristics to similar sequences for natural primes (A006879), cuban primes (A221792) and primes of the form (x+1)^p - x^p for p = 5 (A221847) and p = 7 (A221978).
LINKS
MATHEMATICA
nn = 40; t = Table[0, {nn}]; n = 0; While[n++; p = (n + 1)^11 - n^11; p < 10^nn, If[PrimeQ[p], m = Ceiling[Log[10, p]]; t[[m]]++]]; t (* T. D. Noe, Feb 04 2013 *)
CROSSREFS
Sequence in context: A103778 A099423 A221515 * A071920 A306548 A320531
KEYWORD
nonn,easy,base
AUTHOR
Vladimir Pletser, Feb 02 2013
STATUS
approved