A221846 Number of primes of the form (x+1)^5 - x^5 less than 10^n.

0, 0, 1, 2, 3, 4, 6, 12, 19, 30, 40, 66, 110, 173, 285, 463, 749, 1256, 2075, 3499, 5884, 9928, 16754, 28345, 48037, 82187, 140358, 239768, 409315, 700510, 1200863, 2061093, 3544072, 6098353, 10505051

Offset

0,4

Comments

Number of primes less than 10^n and equal to the difference of two consecutive fifth powers (x+1)^5 - x^5 = 5x(x+1)(x^2+x+1)+1 (A121616). Values of x = A121617. Sequence of number of primes less than 10^n and of the form (x+1)^5 - x^5 have similar characteristics to similar sequences for natural primes (A006880) and cuban primes (A113478).

Links

Table of n, a(n) for n=0..34.

Crossrefs

Sequence in context: A206292 A129297 A337449 * A018343 A242459 A260987

Adjacent sequences: A221843 A221844 A221845 * A221847 A221848 A221849

Keyword

nonn

Author

Vladimir Pletser, Jan 26 2013

Status

approved