|
| |
|
|
A071980
|
|
If n = abcd (say) in decimal, then a(n) = a + ab + abc + abcd + bcd + cd + d.
|
|
1
| |
|
|
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 77, 79
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
EXAMPLE
| a(1347) = 1 + 13 + 134 1347 + 347 + 47 + 7 = 1896.
|
|
|
MATHEMATICA
| f[n_] := Block[{lead = trail = IntegerDigits[n], l = Floor[Log[10, n] + 1], s = -n}, While[l > 0, s = s + FromDigits[lead] + FromDigits[trail]; lead = Drop[lead, -1]; trail = Drop[trail, 1]; l-- ]; s]; Table[ f[n], {n, 0, 80}]
|
|
|
PROG
| (PARI) a(n)=local(l); if(n<1, 0, l=1+log(n)\log(10); sum(i=1, l-1, n\10^i+n%(10^i), n))
|
|
|
CROSSREFS
| Sequence in context: A032959 A061383 A059708 * A058183 A080676 A033061
Adjacent sequences: A071977 A071978 A071979 * A071981 A071982 A071983
|
|
|
KEYWORD
| base,nonn
|
|
|
AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jun 18 2002
|
|
|
EXTENSIONS
| Edited by Robert G. Wilson v (rgwv(AT)rgwv.com), Jun 23 2002
|
| |
|
|
