login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

A092257
Sum_i [i*(i-th digit)] for n-th prime.
0
3, 5, 7, 7, 3, 7, 15, 19, 8, 20, 5, 17, 6, 10, 18, 11, 23, 8, 20, 9, 13, 25, 14, 26, 23, 4, 10, 22, 28, 12, 26, 10, 28, 34, 36, 14, 32, 22, 34, 24, 42, 20, 22, 28, 40, 46, 7, 15, 27, 33, 17, 35, 13, 15, 33, 23, 41, 19, 37, 21, 27, 29, 24, 8, 14, 26, 12, 30, 32, 38, 22, 40, 36, 26, 44
OFFSET
1,1
COMMENTS
The sequence is highly non-monotonic. a(n) appears in the correlation coefficient between digits of p(n) and their indices.
FORMULA
a(n) = Sum_i [i*(i-th digit)] for n-th prime
EXAMPLE
a(7)=15 because p[7]=17 and 1*1+2*7=15
CROSSREFS
Sequence in context: A127314 A294499 A361120 * A316189 A342668 A297346
KEYWORD
easy,nonn,base
AUTHOR
Zak Seidov, Feb 20 2004
STATUS
approved