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A100968 Integers n that are Rhonda numbers to base 4. 19
10206, 11935, 12150, 16031, 45030, 94185, 113022, 114415, 191149, 244713, 259753, 374782, 392121, 503773, 649902, 703326, 716250, 764526, 883630, 884446, 912766, 980694, 980837, 1005502, 1420250, 1474239, 1567335, 1685159, 1702822, 1824634, 1944190, 1948279 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
See sequence of base 10 Rhonda numbers for more information and links.
LINKS
Eric Weisstein's World of Mathematics, Rhonda Number
EXAMPLE
10206 is a Rhonda number to base 4 because the product of its base 4 digits is 2*1*3*3*1*3*2=108, the sum of the prime factors of 10206 is 2+6*3+7=27 and 27*4=108.
Contribution by Reinhard Zumkeller, Mar 05 2015
a(18) = 764526 = 2*4^9 + 3*4^8 + 2*4^7 + 2*4^6 + 2*4^5 + 2*4^4 + 1*4^3 + 2*4^2 + 3*4^1 + 2*4^0 = 2*3*7*109*167
with 2*3*2*2*2*2*1*2*3*2 = 4 * (2+3+7+109+167) = 1152;
a(21) = 912766 = 3*4^9 + 1*4^8 + 3*4^7 + 2*4^6 + 3*4^5 + 1*4^4 + 1*4^3 + 3*4^2 + 3*4^1 + 2*4^0 = 2*53*79*109
with 3*1*3*2*3*1*1*3*3*2 = 4 * (2+53+79+109) = 972. (End)
PROG
(Haskell)
a100968 n = a100968_list !! (n-1)
a100968_list = filter (rhonda 4) a023705_list
-- Function rhonda as in A099542.
-- Reinhard Zumkeller, Mar 08 2015
CROSSREFS
Rhonda numbers to other bases: A100969 (base 6), A100970 (base 8), A100973 (base 9), A099542 (base 10), A100971 (base 12), A100972 (base 14), A100974 (base 15), A100975 (base 16), A255735 (base 18), A255732 (base 20), A255736 (base 30), A255731 (base 60), see also A255872.
Cf. A001414, A027746, A007090, subsequence of A023705.
Column k=1 of A291925.
Sequence in context: A255872 A291925 A255880 * A203056 A252330 A183743
KEYWORD
base,easy,nonn
AUTHOR
Mark Hudson (mrmarkhudson(AT)hotmail.com), Nov 24 2004
EXTENSIONS
a(18) and a(21) corrected, terms a(24) - a(32) by Reinhard Zumkeller, Mar 05 2015
STATUS
approved

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Last modified April 21 13:26 EDT 2024. Contains 371870 sequences. (Running on oeis4.)