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A089369
Begin with n and place (n-1) on the least significant side, place (n-2) on the most significant side and so on until a 1 is placed.
1
1, 21, 132, 2431, 13542, 246531, 1357642, 24687531, 135798642, 24681097531, 1357911108642, 246810121197531, 13579111312108642, 2468101214131197531, 135791113151412108642, 24681012141615131197531
OFFSET
1,2
EXAMPLE
a(6)= 246531, the steps are 6 -> 65 -> 465 -> 4653 -> 24653 -> 246531.
MATHEMATICA
f[n_] := Block[{j = 1, k = n - 1, d = IntegerDigits[n]}, While[k > 0, If[ EvenQ[j], d = Join[ IntegerDigits[k], d], d = Join[d, IntegerDigits[k]]]; j++; k-- ]; FromDigits[d]]; Table[ f[n], {n, 17}]
CROSSREFS
Cf. A089370.
Sequence in context: A008384 A110400 A308348 * A328861 A243201 A264554
KEYWORD
base,easy,nonn
AUTHOR
Amarnath Murthy, Nov 08 2003
EXTENSIONS
More terms from Robert G. Wilson v, Nov 08 2003
STATUS
approved