A277357 a(1) = 1; for n > 1, a(n) = (2^n-1)*a(n-1) + 1.
1, 4, 29, 436, 13517, 851572, 108149645, 27578159476, 14092439492237, 14416565600558452, 29510709784343151245, 120846356566885204348276, 989852506639356708816728717, 16216753616272580960544466570612, 531374365744403660334160536119243405
Offset: 1
Keywords
Crossrefs
Cf. A123672.
Programs
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Mathematica
RecurrenceTable[{a[n]==(2^n-1)*a[n-1]+1, a[1]==1}, a, {n, 1, 15}] -
PARI
a(n) = if (n==1, 1, (2^n-1)*a(n-1) + 1); \\ Michel Marcus, Sep 30 2017
Formula
a(n) ~ c * 2^(n*(n+1)/2), where c = 0.3997494420337372941776146353642774...