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

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

Author

Juri-Stepan Gerasimov, Jun 15 2009

Keywords

• nonn
• base
• less

Examples

			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.
		

Crossrefs

Cf. A000027, A000040, A161570.

Programs

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

Formula

a(n)= A000217(A007652(n)). - R. J. Mathar, Jun 16 2009

Extensions

Definition reworded and a 16 split in 1,6 by R. J. Mathar, Jun 16 2009