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A341756
Records in A341755 (= length of chain of (k,k+1) sharing a digit with k+(k+1), starting at n).
3
2, 5, 6, 20, 28, 48, 170, 274, 350, 1670, 2731, 3350, 16670, 27274, 33350, 166670, 272731, 333350, 1666670, 2727274, 3333350, 16666670, 27272731, 33333350, 166666670
OFFSET
1,1
COMMENTS
The indices of these records, i.e., k such that a(n) = A341755(k) > A341755(m) for all m < k, are listed in A341757.
FORMULA
a(n) = A341755(A341757(n)).
Conjecture: | a(n+3)/10 - a(n) | <= 10 for all n except n = 6; specifically:
a(3n+6) = 3...350 with n '3's, n >= 1;
a(3n+7) = 16...670 with n '6's, n >= 0.
EXAMPLE
After {0, 1}, the first nontrivial chain is {9, 10, 11, 12, 13} with 5 members.
The chain of length 48 starting at 486 contains a somewhat "trivial" chain starting at 500: the shared digit of the first 10 terms is the '0' of 10** and 50*, the shared digit of the next 10-11 terms is the '1' of 10** and 51*.
PROG
(PARI) lista(nn) = my(m, t); for(k=0, nn, if(t=A341755(k), if(t>m, print1(m=t, ", ")); k+=t-1)) \\ modified by Jinyuan Wang, Mar 13 2021
CROSSREFS
Sequence in context: A282536 A248719 A184594 * A014454 A136324 A128367
KEYWORD
nonn,base,more
AUTHOR
M. F. Hasler, Mar 01 2021
EXTENSIONS
a(14)-a(25) from Jinyuan Wang, Mar 13 2021
STATUS
approved