



0, 0, 1, 1, 1, 0, 2, 3, 5, 2, 0, 6, 3, 5, 3, 8, 8, 5, 1, 5, 4, 1, 5, 5, 3, 6, 7, 2, 7, 6, 13, 0, 2, 1, 3, 0, 9, 2, 6, 4, 16, 10, 4, 2, 11, 16, 11, 10, 6, 6, 4, 22, 4, 12, 1, 3, 8, 5, 15, 15, 6, 8, 0, 2, 13, 2, 7, 8, 17, 4, 8, 25, 0, 9, 8, 10, 10, 9, 2, 21, 4, 2, 18, 15, 12, 4, 6, 10, 19, 5, 17, 23, 14, 28, 5, 4, 6, 3, 16, 2
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OFFSET

0,7


COMMENTS

Conjectured to increase to infinity. It appears that the slope of A004090(n) is roughly 0.93, at least in the range 0..10^5.
I conjecture that this sequence takes its minimum at a(2619) = 92.  M. F. Hasler, Dec 30 2016


LINKS

M. F. Hasler, Table of n, a(n) for n = 0..100000


FORMULA

a(n) = n  A004090(n) = n  A007953(A000045(n)).


EXAMPLE

a(2) = a(3) = 1 because A000045(2) = 1 = A004090(2), its digital sum, A000045(3) = 2 = A004090(3), and 2  1 = 3  2 = 1.


MATHEMATICA

Table[n  Total@ IntegerDigits@ Fibonacci@ n, {n, 0, 99}] (* Michael De Vlieger, Dec 28 2016 *)


PROG

(PARI) A280185(n)=nsumdigits(fibonacci(n))
/* To produce the bfile; can be used for searches or similar purpose, this is faster than to compute fib(n) anew for each term. */
b=a=1; for(n=0, 1e5, write("/tmp/A280185.txt", n" ", nsumdigits(a=b+b=a)))


CROSSREFS

Cf. A000045 (Fibonacci numbers), A004090 (their digital sums), A278834 & A278833 (record values of this sequence and corresponding indices), A264935.
Sequence in context: A069111 A171035 A094122 * A082117 A269701 A011157
Adjacent sequences: A280182 A280183 A280184 * A280186 A280187 A280188


KEYWORD

sign,base


AUTHOR

M. F. Hasler, Dec 28 2016


STATUS

approved



