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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..80.

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

Cf. A000027, A000040, A161570.

Sequence in context: A165729 A056278 A000740 * A234848 A300761 A069712

Adjacent sequences:  A161622 A161623 A161624 * A161626 A161627 A161628

KEYWORD

nonn,base,less

AUTHOR

Juri-Stepan Gerasimov, Jun 15 2009

EXTENSIONS

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

STATUS

approved

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Last modified July 13 07:54 EDT 2020. Contains 335685 sequences. (Running on oeis4.)