A374908 Each term is the sum of the preceding term and its seven-segment total A006942.
0, 6, 12, 19, 27, 35, 45, 54, 63, 74, 81, 90, 102, 115, 124, 135, 147, 156, 169, 183, 197, 208, 226, 242, 256, 272, 285, 302, 318, 332, 347, 359, 375, 388, 407, 420, 435, 449, 463, 478, 492, 507, 521, 533, 548, 564, 579, 593, 609, 627, 641, 653, 669, 687, 703
Offset: 0
Examples
For n=1, the preceding a(0) = 0 is 6 segments so that a(1) = 0 + 6 = 6.
Links
- Dominic McCarty, Table of n, a(n) for n = 0..10000
Programs
-
Mathematica
s={0};Do[AppendTo[s,Last[s]+ Plus @@ (IntegerDigits@ Last[s] /. {0 -> 6, 1 -> 2, 2 -> 5, 3 -> 5, 7 -> 3, 8 -> 7, 9 -> 6})],{n,54}];s (* James C. McMahon, Aug 19 2024 *) -
Python
from itertools import islice def b(n): return sum([6, 2, 5, 5, 4, 5, 6, 3, 7, 6][int(d)] for d in str(n)) def agen(): # generator of terms yield (an:=0) while True: yield (an:=an+b(an)) print(list(islice(agen(), 55))) # Michael S. Branicky, Jul 28 2024
Formula
a(n) = a(n-1) + A006942(a(n-1)).
Comments