The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A274698 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A274698

a(n)=prime(n)-(2*last digit of prime(n)).
(history; published version)

#10 by Alois P. Heinz at Mon Oct 04 13:14:01 EDT 2021

STATUS

proposed

approved

#9 by Michel Marcus at Mon Oct 04 09:28:56 EDT 2021

STATUS

editing

proposed

#8 by Michel Marcus at Mon Oct 04 09:28:52 EDT 2021

EXAMPLE

For n=9, prime(9)=23. Last digit of 23 is 3, 23-2*3 = 17. So a(9) = 17 is term.

STATUS

approved

editing

#7 by N. J. A. Sloane at Sat Jul 02 23:51:34 EDT 2016

STATUS

editing

approved

#6 by N. J. A. Sloane at Sat Jul 02 23:51:32 EDT 2016

COMMENTS

a(n) is symmetric to the decade in which belongs the prime number. For example 37=30+7. So a(12)=30-7=23 and 23,37 are symmetric to the 30.

KEYWORD

sign,changed,base,less

STATUS

proposed

editing

#5 by Dimitris Valianatos at Sat Jul 02 19:08:03 EDT 2016

STATUS

editing

proposed

#4 by Dimitris Valianatos at Sat Jul 02 19:07:58 EDT 2016

COMMENTS

a(n) is symmetric to the decade in which belongs the prime number. For example 37=30+7. So a(12)=30-7=23 and 23,37 are symmetric to the 30.

STATUS

proposed

editing

#3 by Dimitris Valianatos at Sat Jul 02 18:48:03 EDT 2016

STATUS

editing

proposed

#2 by Dimitris Valianatos at Sat Jul 02 18:47:56 EDT 2016

NAME

allocated for Dimitris Valianatosa(n)=prime(n)-(2*last digit of prime(n)).

DATA

-2, -3, -5, -7, 9, 7, 3, 1, 17, 11, 29, 23, 39, 37, 33, 47, 41, 59, 53, 69, 67, 61, 77, 71, 83, 99, 97, 93, 91, 107, 113, 129, 123, 121, 131, 149, 143, 157, 153, 167, 161, 179, 189, 187, 183, 181, 209, 217, 213, 211, 227, 221, 239, 249, 243

OFFSET

1,1

EXAMPLE

For n=9, prime(9)=23. Last digit of 23 is 3, 23-2*3 = 17. So a(9)=17 is term.

PROG

(PARI) {

forprime(n=1, 300,

p=floor(n/10)*10;

d=n-p;

pd=p-d;

print1(pd", ")

)

}

KEYWORD

allocated

sign

AUTHOR

Dimitris Valianatos, Jul 02 2016

STATUS

approved

editing

#1 by Dimitris Valianatos at Sat Jul 02 18:47:56 EDT 2016

NAME

allocated for Dimitris Valianatos

KEYWORD

allocated

STATUS

approved