A100968 - OEIS

A100968

Integers n that are Rhonda numbers to base 4.

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

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

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.

From Reinhard Zumkeller, Mar 05 2015: (Start)

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

Adjacent sequences: A100965 A100966 A100967 * A100969 A100970 A100971

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