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A161625
Sum of all numbers from 1 up to the final digit of prime(n).
1
3, 6, 15, 28, 1, 6, 28, 45, 6, 45, 1, 28, 1, 6, 28, 6, 45, 1, 28, 1, 6, 45, 6, 45, 28, 1, 6, 28, 45, 6, 28, 1, 28, 45, 45, 1, 28, 6, 28, 6, 45, 1, 1, 6, 28, 45, 1, 6, 28, 45, 6, 45, 1, 1, 28, 6, 45, 1, 28, 1, 6, 6, 28, 1, 6, 28, 1, 28, 28, 45, 6, 45, 28, 6, 45, 6, 45, 28, 1, 45
OFFSET
1,1
FORMULA
a(n)= A000217(A007652(n)). - R. J. Mathar, Jun 16 2009
EXAMPLE
a(1)=3=1+2. a(2)=6=1+2+3. a(3)=15=1+2+3+4+5. a(4)=28=1+2+3+4+5+6+7. a(5)=1=1. a(6)=3=1+2.
MAPLE
A007652 := proc(n) ithprime(n) mod 10; end: A000217 := proc(n) n*(n+1)/2 ; end:
A161625 := proc(n) A000217(A007652(n)) ; end: seq(A161625(n), n=1..80) ; # R. J. Mathar, Jun 16 2009
CROSSREFS
KEYWORD
nonn,base,less
AUTHOR
EXTENSIONS
Definition reworded and a 16 split in 1,6 by R. J. Mathar, Jun 16 2009
STATUS
approved