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A176266
Binomial(prime(n),s)/prime(n) where s is the sum of the decimal digits of n.
2
1, 1, 2, 5, 42, 132, 1144, 3978, 35530, 1, 15, 210, 2470, 22386, 228459, 2908360, 37584261, 284291205, 3701413144, 35, 852, 19019, 349812, 6529292, 132435472, 2000945100, 24366118700, 328386663605, 3520256293710, 2072, 81375, 2271776, 59988852, 1227434238, 33401522154, 584134601050, 11919696387170, 234924043375476, 3924875235562164, 208335
OFFSET
1,3
COMMENTS
For n = 10^p, a(n) = 1.
FORMULA
a(n) = A007318( A000040(n), A007953(n))/A000040(n).
a(n) = A060604(n)/A000040(n), n<10.
EXAMPLE
a(5) = 42 because prime(5) = 11, s = 5, binomial(11,5)/11 = 462/11=42.
a(16)=2908360 because prime(16)=53, s=7, binomial(53,7)/53 =154143080/53 = 2908360.
MAPLE
A176266 := proc(n) binomial(ithprime(n), A007953(n))/ithprime(n) ; end proc:
seq(A176266(n), n=1..20) ;
MATHEMATICA
Table[Binomial[Prime[n], Total[IntegerDigits[n]]]/Prime[n], {n, 40}] (* Harvey P. Dale, Oct 25 2020 *)
PROG
(Sage) A176266 = lambda n: binomial(nth_prime(n), sum(n.digits()))/nth_prime(n) # D. S. McNeil, Dec 08 2010
CROSSREFS
Cf. A075872.
Sequence in context: A255963 A093625 A042447 * A075872 A075891 A246669
KEYWORD
nonn,base
AUTHOR
Michel Lagneau, Dec 07 2010
STATUS
approved