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A161625 Sum of all numbers from 1 up to the final digit of prime(n). 1

%I

%S 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,

%T 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,

%U 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

%N Sum of all numbers from 1 up to the final digit of prime(n).

%F a(n)= A000217(A007652(n)). - _R. J. Mathar_, Jun 16 2009

%e 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.

%p A007652 := proc(n) ithprime(n) mod 10; end: A000217 := proc(n) n*(n+1)/2 ; end:

%p A161625 := proc(n) A000217(A007652(n)) ; end: seq(A161625(n),n=1..80) ; # _R. J. Mathar_, Jun 16 2009

%Y Cf. A000027, A000040, A161570.

%K nonn,base,less

%O 1,1

%A _Juri-Stepan Gerasimov_, Jun 15 2009

%E Definition reworded and a 16 split in 1,6 by _R. J. Mathar_, Jun 16 2009

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Last modified August 10 16:56 EDT 2020. Contains 336381 sequences. (Running on oeis4.)