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A175038
In the sequence of positive integers A000027, number of digits between successive primes.
2
0, 1, 1, 4, 2, 6, 2, 6, 10, 2, 10, 6, 2, 6, 10, 10, 2, 10, 6, 2, 10, 6, 10, 14, 7, 3, 9, 3, 9, 39, 9, 15, 3, 27, 3, 15, 15, 9, 15, 15, 3, 27, 3, 9, 3, 33, 33, 9, 3, 9, 15, 3, 27, 15, 15, 15, 3, 15, 9, 3, 27, 39, 9, 3, 9, 39, 15, 27, 3, 9, 15, 21, 15, 15, 9, 15, 21, 9, 21, 27, 3, 27, 3, 15, 9, 15
OFFSET
1,4
COMMENTS
From Jamie Morken, Feb 01 2019: (Start)
For A006880(m) < n < A006880(m+1), a(n) = A046933(n)*(m + 1).
For example m=1, n=24 then a(n)=7*2=14.
For example m=2, n=26 then a(n)=1*3=3.
For n = A006880(m+1), a(n) = A046933(n)*(m+1) + A033873(m + 1).
For example m=1, n=25 then a(n)=3*2+1=7.
(End)
LINKS
EXAMPLE
a(4) = 4 as prime(4) = 7 and prime(4+1) = 11 so the number of digits between these two primes is the number of digits of 8, 9 and 10. These numbers have 4 digits combined. Therefore a(4) = 4. - David A. Corneth, Jan 30 2019
MATHEMATICA
Table[Length[Flatten[IntegerDigits/@Range[Prime[n]+1, Prime[n+1]-1]]], {n, 200}]
PROG
(PARI) a(n) = sum(k=prime(n)+1, prime(n+1)-1, #Str(k)); \\ Michel Marcus, Jan 30 2019
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Zak Seidov, Nov 13 2009
STATUS
approved