

A004665


Powers of 3 written in base 11. (Next term contains a nondecimal character.)


1




OFFSET

0,2


COMMENTS

The next term contains a nondecimal character if such a character (e.g., 'A') is chosen to represent a digit 10, where "digit" means the coefficients in N = Sum_{k>=0} d_k * 11^k. A different "encoding" has to be used to represent such terms in the Data sections of OEIS entries. In order to preserve the terms a(0..7), one could use the twodigit combinations '08' and '18' to encode the digits 8 (the only one not occurring so far) and 10.  M. F. Hasler, Jun 25 2018


LINKS



MATHEMATICA

FromDigits[IntegerDigits[#, 11]]&/@(3^Range[0, 7]) (* Harvey P. Dale, Jul 31 2013 *)


PROG

(PARI) apply( A004665(n)=if(vecmax(n=digits(3^n, 11))>9, Strchr(apply(d>48+d+(d>9)*7, n)), fromdigits(n)), [0..10]) \\ Slightly shorter but slower: {a(n)=iferr(eval(n=Strchr(apply(d>48+d+(d>9)*7, digits(3^n, 11)))), E, n)}.  M. F. Hasler, Jun 25 2018


CROSSREFS



KEYWORD

nonn,base


AUTHOR



STATUS

approved



