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A226092 Fourth powers that become prime when their most significant (leftmost) decimal digit is removed. 2
2401, 279841, 15752961, 20151121, 35153041, 43046721, 62742241, 68574961, 88529281, 200533921, 260144641, 547981281, 671898241, 2385443281, 2655237841, 2750058481, 2847396321, 3262808641, 3722098081, 4640470641, 5887339441, 6414247921, 8428892481, 8882874001 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This is to fourth powers A000583 as A226090 is to as cubes A000578, and as A225873 is to squares A000290.

LINKS

Table of n, a(n) for n=1..24.

EXAMPLE

a(1) = 7^4 = 2401, because removing the leftmost digit (4) leaves 401, which is prime.

a(2) = 23^4 = 279841, because removing the leftmost digit (2) leaves 79841, which is prime.

a(3) = 63^4 = 15752961, because removing the leftmost digit (1) leaves 5752961, which is prime.

a(10) = 119^4 = 200533921, because removing the leftmost digit (2) leaves 00533921 = 533921, which is prime.

MATHEMATICA

Select[Range[307]^4, PrimeQ@Mod[#, 10^IntegerLength@#/10] &] (* Giovanni Resta, May 26 2013 *)

CROSSREFS

Cf. A000583, A225873, A226090.

Sequence in context: A017476 A017608 A061210 * A097015 A222461 A013845

Adjacent sequences:  A226089 A226090 A226091 * A226093 A226094 A226095

KEYWORD

nonn,base,easy

AUTHOR

Jonathan Vos Post, May 26 2013

EXTENSIONS

a(13)-a(24) from Giovanni Resta, May 26 2013

STATUS

approved

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Last modified July 24 20:26 EDT 2021. Contains 346273 sequences. (Running on oeis4.)