(Translated by https://www.hiragana.jp/)
A037492 - OEIS
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A037492
Base 7 digits are, in order, the first n terms of the periodic sequence with initial period 2,1.
0
2, 15, 107, 750, 5252, 36765, 257357, 1801500, 12610502, 88273515, 617914607, 4325402250, 30277815752, 211944710265, 1483612971857, 10385290803000, 72697035621002, 508879249347015, 3562154745429107
OFFSET
1,1
FORMULA
a(n) = 7*a(n-1) + a(n-2) - 7*a(n-3).
G.f.: x*(2+x) / ( (x-1)*(7*x-1)*(1+x) ). - R. J. Mathar, Nov 21 2011
CROSSREFS
Sequence in context: A037733 A308938 A037556 * A037572 A218686 A279087
KEYWORD
nonn,base,easy
STATUS
approved