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A025707 Index of 5^n within sequence of numbers of form 5^i*6^j. 2
1, 2, 4, 7, 11, 16, 22, 29, 37, 46, 55, 65, 76, 88, 101, 115, 130, 146, 163, 181, 199, 218, 238, 259, 281, 304, 328, 353, 379, 406, 433, 461, 490, 520, 551, 583, 616, 650, 685, 721, 757, 794, 832, 871, 911, 952, 994, 1037, 1081, 1126, 1171, 1217, 1264, 1312, 1361 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 0..10000

PROG

(PARI) a(n)=my(N=1); n+1+sum(i=1, n, logint(N*=5, 6)); \\ Charles R Greathouse IV, Jan 11 2018

(PARI) first(n)=my(s, N=1/5); vector(n+1, i, s+=logint(N*=5, 6)+1) \\ Charles R Greathouse IV, Jan 11 2018

CROSSREFS

Sequence in context: A348400 A025726 A070280 * A337919 A025733 A025716

Adjacent sequences:  A025704 A025705 A025706 * A025708 A025709 A025710

KEYWORD

nonn,easy

AUTHOR

David W. Wilson

EXTENSIONS

Offset corrected by Charles R Greathouse IV, Jan 11 2018

STATUS

approved

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Last modified December 6 20:22 EST 2021. Contains 349567 sequences. (Running on oeis4.)