OFFSET
0,3
COMMENTS
The first 10 terms are given by a simple explicit formula and linear recurrence, which does not hold for n > 9. Note that A007908 (concat(1..n)) differs from A014824 (a(n) = a(n-1)*10 + n) for n > 9. - M. F. Hasler, Nov 07 2020
LINKS
M. F. Hasler, Table of n, a(n) for n = 0..100
FORMULA
a(n) = A083449(n) + 1 for n <= 9.
PROG
(PARI) print1(c=1); N=0; for(n=1, 8, print1(", "c+=sum(k=N+1, N=N*10+n, #select(d->d==0, digits(k))))) \\ For purpose of illustration.
(PARI) apply( A277830(n)={A061217(A014824(n)+!n)+1}, [0..22]) \\ Thanks to Kevin Ryde's formula. - M. F. Hasler, Nov 07 2020
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
M. F. Hasler, Nov 01 2016
EXTENSIONS
Incorrect data, b-file, links, formulas and programs deleted by M. F. Hasler, following observations by Kevin Ryde, Nov 07 2020
STATUS
approved